Note – Occidental Petroleum Corp.

The information in this preliminary prospectus supplement and the
accompanying prospectus is not complete and may be changed. This preliminary
prospectus supplement and the accompanying prospectus are not an offer to sell
the notes or a solicitation of an offer to buy the notes in any jurisdiction
where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 15, 2011

Preliminary Prospectus Supplement
(To Prospectus dated August 15, 2011)

$ % Senior Notes due 20

$ % Senior Notes due 20

We are offering $ aggregate principal amount of our % senior notes due 20 and
$ aggregate principal amount of our % senior notes due 20 .

In this prospectus supplement, we refer to the % senior notes due 20 as the
“20 notes” and the % senior notes due 20 as the “20 notes” and the 20 notes and
the 20 notes together as the “notes”. We will pay interest on the notes of each
series on and of each year, beginning , 2012. The 20 notes will mature on , 20
and the 20 notes will mature on , 20 . We may redeem some or all of the notes of
either series at our option at any time and from time to time at the redemption
prices described under “Description of the Notes:Optional Redemption” in this
prospectus supplement.

The notes will be our unsecured senior obligations and will rank equally in
right of payment with all of our other unsecured senior indebtedness from time
to time outstanding. The notes will be issued only in denominations of $2,000
and integral multiples of $1,000 in excess thereof. The notes will not be listed
on any securities exchange.

Investing in the notes involves risks. Please read “Risk Factors”
beginning on page S-1 of this prospectus supplement and in our Annual Report on
Form 10-K for the year ended December 31, 2010, which is incorporated by
reference into this prospectus supplement and the accompanying
prospectus.

(1)

Plus accrued interest, if any, from August , 2011.

Neither the Securities and Exchange Commission nor any state
securities commission has approved or disapproved of these securities or
determined if this prospectus supplement or the accompanying prospectus is
truthful or complete. Any representation to the contrary is a criminal
offense.

The notes will be delivered to investors on or about August , 2011 in
book-entry form only through the facilities of The Depository Trust Company for
the accounts of its participants, which may include Clearstream Banking,
soci t anonyme, and Euroclear Bank S.A./N.V., against payment in New
York, New York.

Joint Book-Running Managers

August , 2011

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS SUPPLEMENT

No action has been or will be taken in any jurisdiction by us or by any
underwriter that would permit a public offering of the notes or the possession
or distribution of this prospectus supplement, the accompanying prospectus or
any related free writing prospectus in any jurisdiction where action for that
purpose is required, other than the United States. Unless otherwise expressly
stated or the context otherwise requires, references to “dollars,” “$” and other
similar references in this prospectus supplement, the accompanying prospectus
and any related free writing prospectuses are to U.S. dollars.

No person is authorized to give any information or to make any
representations other than those contained or incorporated by reference in this
prospectus supplement, the accompanying prospectus or any free writing
prospectus we may provide to you in connection with this offering and, if given
or made, such information or representations must not be relied upon as having
been authorized. This prospectus supplement, the accompanying prospectus and any
such free writing prospectus do not constitute an offer to sell or the
solicitation of an offer to buy any securities other than the securities
described in this prospectus supplement or an offer to sell or the solicitation
of an offer to buy those securities in any circumstances or jurisdiction in
which such offer or solicitation is unlawful.

Unless otherwise expressly stated or the context otherwise requires, the
words “Occidental,” “we,” “us” and “our” as used in this prospectus supplement
refer only to Occidental Petroleum Corporation and not to any of its
subsidiaries.

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RISK FACTORS

Investing in the notes involves risks. You should carefully consider the
following risk factors, in addition to the other information contained or
incorporated by reference in this prospectus supplement and the accompanying
prospectus. Specifically, please see “Risk Factors” included in our Annual
Report on Form 10-K for the year ended December 31, 2010 and the other
information in that and the other reports that we file with the Securities and
Exchange Commission, or SEC, that are incorporated by reference in this
prospectus supplement for a discussion of risk factors that may affect our
business. Realization of any of those risks or the following risks or adverse
results from any matter listed under the heading “Forward-Looking Statements” in
the accompanying prospectus or in any such reports could have a material adverse
effect on our business, financial condition, cash flows and results of
operations, and you might lose all or part of your investment.

Risks Related to the Notes

The notes will be effectively subordinated to the indebtedness
and other liabilities of our subsidiaries.

Substantially all of our operations are conducted through our subsidiaries.
None of our subsidiaries is a guarantor of the notes. As a result, our right to
receive assets upon the liquidation or recapitalization of any of our
subsidiaries, and your consequent right to benefit from our receipt of those
assets, will be subject to the claims of such subsidiary’s creditors.
Accordingly, the notes are effectively subordinated to all indebtedness and
other liabilities, including trade payables, of our subsidiaries. Even if we
were recognized as a creditor of one or more of our subsidiaries, our claims
would still be effectively subordinated to any security interests in or other
liens on the assets of any such subsidiary and to any indebtedness or other
liabilities of any such subsidiary senior to our claims.

In addition, we derive substantially all of our revenues from our
subsidiaries. As a result, our cash flow and our ability to service our debt and
other obligations, including the notes, will depend on the results of operations
of our subsidiaries and upon the ability of our subsidiaries to provide us with
cash to pay amounts due on our obligations, including the notes. Our
subsidiaries are separate and distinct legal entities and have no obligation to
make payments on the notes or to make funds available to us for that purpose. In
addition, dividends, loans or other distributions from our subsidiaries to us
may be subject to contractual and other restrictions, are dependent upon results
of operations of our subsidiaries, may be subject to tax or other laws limiting
our ability to repatriate funds from foreign subsidiaries and may be subject to
other business considerations.

The notes will be unsecured and therefore will be effectively
subordinated to any secured indebtedness we may incur.

The notes will not be secured by any of our assets. As a result, the notes
will be effectively subordinated to any secured debt we or our subsidiaries may
incur in the future to the extent of the value of the assets securing such debt.
In any liquidation, dissolution, bankruptcy or other similar proceeding, the
holders of any of our secured debt and the secured debt of our subsidiaries may
assert rights against the assets pledged to secure that debt in order to receive
full payment of their debt before the assets may be used to pay other creditors,
including the holders of the notes.

Our credit ratings may not reflect all risks of an investment in
the notes and there is no protection in the indenture for holders of the notes
in the event of a ratings downgrade.

Our credit ratings are an assessment by rating agencies of our ability to pay
our debts when due but they may not reflect the potential impact of all risks
related to an investment in the notes. Consequently, real or anticipated changes
in our credit ratings will generally affect the market value of the notes.
Credit ratings are not a recommendation to buy, sell or hold any security, and
may be revised or withdrawn at any time by the issuing organization in its sole
discretion. We have no

S-1

obligation to maintain the ratings and neither we nor any underwriter
undertakes any obligation to advise holders of notes of any change in ratings.
Each agency’s rating should be evaluated independently of any other agency’s
rating.

The indenture does not limit the amount of indebtedness that we
or our subsidiaries may incur.

The indenture does not limit our ability or that of our subsidiaries to incur
additional indebtedness or contain provisions that would afford holders of the
notes protection in the event of a decline in our credit quality or a take-over,
recapitalization or highly leveraged or similar transaction. Accordingly, we and
our subsidiaries could, in the future, enter into transactions that could
increase the amount of indebtedness outstanding at that time or otherwise
adversely affect your position in our consolidated capital structure or our
credit ratings.

If an active trading market does not develop for the notes, you
may be unable to sell your notes or to sell your notes at a price that you deem
sufficient.

The notes are a new issue of securities with no established trading market,
and we do not intend to list them on any securities exchange or automated
quotation system. As a result, an active trading market for the notes may not
develop, or if one does develop, it may not be sustained. If an active trading
market fails to develop or cannot be sustained, you may not be able to resell
your notes at their fair market value or at all.

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OCCIDENTAL

Our principal businesses consist of three segments operated by our
subsidiaries and affiliates. The oil and gas segment explores for, develops,
produces and markets crude oil, including natural gas liquids (NGLs) and
condensate (together with NGLs, “liquids”), as well as natural gas. The chemical
segment manufactures and markets basic chemicals, vinyls and other chemicals.
The midstream, marketing and other segment gathers, treats, processes,
transports, stores, purchases and markets crude oil, liquids, natural gas,
carbon dioxide and power. It also trades around its assets, including pipelines
and storage capacity, and trades oil and gas, other commodities and
commodity-related securities. Our principal executive offices are located at
10889 Wilshire Boulevard, Los Angeles, California 90024, telephone (310)
208-8800.

USE OF PROCEEDS

The net proceeds from this offering are expected to be approximately $
million, after deducting the underwriting discounts and our estimated offering
expenses. We intend to use the net proceeds from the sale of the notes for
general corporate purposes, which may include ordinary course working capital
increases, acquisitions, retirement of debt, stock repurchases and other
business opportunities.

S-3

DESCRIPTION OF THE NOTES

The 20 and the 20 notes will each constitute a separate series of senior debt
securities under an indenture (the “indenture”) to be entered into between us
and The Bank of New York Mellon Trust Company, N.A., as trustee. We will issue
the notes under an officers’ certificate pursuant to such indenture setting
forth the specific terms applicable to such notes. References to the “indenture”
in this description mean such indenture as so supplemented by such certificate.

The following description is a summary of some of the provisions of the notes
and the indenture. This summary is not complete and is qualified in its entirety
by reference to the indenture. You should carefully read the summary below, the
description of the general terms and provisions of our senior debt securities
set forth in the accompanying prospectus under the heading “Description of
Senior Debt Securities” and the indenture before investing in the notes.

This description of the notes supplements and, to the extent it is
inconsistent, replaces the description of the general provisions of the senior
debt securities and the indenture in the accompanying prospectus. The notes are
“senior debt securities” as that term is used in the accompanying prospectus,
the indenture is referred to in the accompanying prospectus as the “Senior
Indenture” and the trustee is referred to in the accompanying prospectus as the
“Senior Indenture Trustee.” In this description, the term “Securities” refers to
all senior debt securities that may be issued under the indenture and includes
the notes.

Description of the Notes

The notes are unsecured and will rank equally in right of payment with all of
our other senior unsecured indebtedness. The indenture does not limit the
aggregate principal amount of Securities that we may issue under the indenture
and we may, without the consent of holders of outstanding Securities, issue
additional Securities thereunder. In addition, the indenture does not limit the
amount of other unsecured debt that we or our subsidiaries may issue or incur.
Such other unsecured debt may have different terms than the notes. Our
previously issued and outstanding senior debt does have different terms than the
notes (including different restrictive covenants and event of default
provisions). The terms of the notes will only be as described in the indenture,
the accompanying prospectus and this prospectus supplement. As of June 30, 2011,
we had approximately $4.3 billion of senior debt securities outstanding which
ranked equally in right of payment with the notes.

Substantially all of our operations are conducted through our subsidiaries.
None of our subsidiaries is a guarantor of the notes. As a result, our right to
receive assets upon the liquidation or recapitalization of any of our
subsidiaries, and your consequent right to benefit from our receipt of those
assets, will be subject to the claims of such subsidiary’s creditors.
Accordingly, the notes are effectively subordinated to all indebtedness and
other liabilities, including trade payables, of our subsidiaries. Even if we
were recognized as a creditor of one or more of our subsidiaries, our claims
would still be effectively subordinated to any security interests in or other
liens on the assets of any such subsidiary and to any indebtedness or other
liabilities of any such subsidiary senior to our claims.

Principal, Maturity and Interest

The 20 notes will be initially limited to $ aggregate principal amount, and
the 20 notes will be initially limited to $ aggregate principal amount. The 20
notes will mature on , 20 and the 20 notes will mature on , 20 . We may, from
time to time, without the consent of the holders of the notes of any series,
reopen the 20 notes or the 20 notes or both and issue additional notes of such
series.

Interest on the 20 notes will accrue at the rate of % per year, and interest
on the 20 notes will accrue at the rate of % per year. Interest on the notes
will be payable semi-annually in

S-4

arrears on and , commencing on , 2012. We will make each interest payment to
the holders of record of the notes at the close of business on the immediately
preceding and , respectively.

If any interest payment date, maturity date or redemption date for the 20
notes or the 20 notes falls on a day that is not a business day, the payment
will be made on the next business day, and no interest will accrue on that
payment for the period from and after such interest payment date, maturity date
or redemption date until such following business day.

Interest on the 20 notes and the 20 notes will accrue from August , 2011 and
will be computed on the basis of a 360-day year comprised of twelve 30-day
months.

Interest payable on any interest payment date or on the maturity date of the
20 notes or the 20 notes shall be the amount of interest accrued from, and
including, the immediately preceding interest payment date in respect of which
interest has been paid or duly provided for on the notes of such series (or from
and including the original issue date of the notes of such series, if no
interest has been paid or duly provided for on the notes of such series) to, but
not including, such interest payment date or maturity date, as the case may be.

Place of Payment, Transfer and Exchange

All payments on the notes will be made, and transfers of the notes will be
registrable, at the trustee’s office in The City of New York, unless we
designate another place for such purpose.

Optional Redemption

The 20 notes are redeemable at our option, in whole at any time or in part
from time to time, and the 20 notes are redeemable at our option, in whole at
any time or in part from time to time prior to , 20 , at a redemption price
equal to the greater of:

100% of the principal amount of the notes of such series to be redeemed; and

the sum of the present values of the remaining scheduled payments of
principal and interest on the notes of such series to be redeemed (not including
any portion of such payments of interest accrued to the redemption date)
discounted to the redemption date on a semi-annual basis (assuming a 360-day
year comprised of twelve 30-day months) at the Adjusted Treasury Rate plus basis
points, in the case of the 20 notes, and basis points, in the case of the 20
notes;

plus, in each case, accrued and unpaid interest on the principal amount of
the notes of such series being redeemed to the redemption date.

On and after 20 , the 20 notes are redeemable at our option, in whole at any
time or in part from time to time, at a redemption price equal to 100% of the
principal amount of the 20 notes to be redeemed, plus accrued and unpaid
interest on the principal amount of the 20 notes being redeemed to the
redemption date.

Notwithstanding the foregoing, with respect to payments of interest on the 20
notes or the 20 notes that are due and payable on any interest payment dates
falling on or prior to a redemption date for the notes of such series, we will
make such payments to the record holders of such notes at the close of business
on the relevant regular record dates.

We will send to each holder of the 20 notes or the 20 notes, as applicable,
notice of any redemption of notes of such series at least 30 days but not more
than 60 days before the applicable redemption date. Unless we default in payment
of the redemption price (or accrued and unpaid interest) with respect to the
notes to be redeemed, no interest will accrue on the notes or portions

S-5

thereof so redeemed for the period on and after such redemption date. If less
than all of the notes of such series are to be redeemed, the trustee will select
the notes (or portions thereof) to be redeemed by such method as the trustee
deems fair and appropriate.

“Adjusted Treasury Rate” means, with respect to any redemption date for the
20 notes or the 20 notes, as applicable, the rate per year equal to the
semi-annual equivalent yield to maturity of the Comparable Treasury Issue,
assuming a price for the Comparable Treasury Issue (expressed as a percentage of
its principal amount) equal to the Comparable Treasury Price for such redemption
date.

“Comparable Treasury Issue” means, with respect to any redemption date for
the 20 notes or the 20 notes, as applicable, the United States Treasury security
selected by the Quotation Agent as having a maturity comparable to the remaining
term of the notes of such series to be redeemed that would be utilized, at the
time of selection and in accordance with customary financial practice, in
pricing new issues of corporate debt securities of comparable maturity to the
remaining term of the notes of such series.

“Comparable Treasury Price” means, with respect to any redemption date for
the 20 notes or the 20 notes, as applicable, (1) the average of the Reference
Treasury Dealer Quotations for such redemption date, after excluding the highest
and lowest Reference Treasury Dealer Quotations, or (2) if the trustee obtains
fewer than three Reference Treasury Dealer Quotations, the average of all such
Reference Treasury Dealer Quotations, such average in any case to be determined
by the Quotation Agent, or (3) if only one Reference Treasury Dealer Quotation
is received, such Reference Treasury Dealer Quotation.

“Quotation Agent” means, with respect to any redemption date for the 20 notes
or the 20 notes, as applicable, the Reference Treasury Dealer appointed by us.

“Reference Treasury Dealer” means, with respect to any redemption date for
the 20 notes or the 20 notes, as applicable, (1) Barclays Capital Inc.,
Citigroup Global Markets Inc. and J.P. Morgan Securities LLC (or their
respective affiliates which are primary U.S. Government securities dealers) and
their respective successors; provided, however, that if any of them shall cease
to be a primary U.S. Government securities dealer in the United States of
America (a “Primary Treasury Dealer”), we will substitute for it another Primary
Treasury Dealer and (2) any other Primary Treasury Dealer or Dealers selected by
us.

“Reference Treasury Dealer Quotations” means, with respect to each Reference
Treasury Dealer and any redemption date for the 20 notes or the 20 notes, as
applicable, the average, as determined by the Quotation Agent, of the bid and
asked prices for the Comparable Treasury Issue (expressed in each case as a
percentage of its principal amount) quoted in writing to the trustee by such
Reference Treasury Dealer at 5:00 p.m. on the third business day in The City of
New York preceding such redemption date.

Discharge

We may terminate at any time our obligations under the indenture with respect
to either or both series of notes (other than certain limited obligations, such
as the obligation to transfer and exchange the notes of that series) by (1)(a)
delivering all of the notes of that series to the trustee to be cancelled or (b)
depositing with the trustee in trust funds or non-callable United States
government or government-guaranteed obligations sufficient without reinvestment
to pay all remaining principal and interest on the notes of that series and (2)
complying with certain other provisions of the indenture.

If we elect to discharge our obligations with respect to either or both
series of notes by depositing cash or United States government or government
guaranteed obligations as described above, under present law such discharge is
likely to be treated for United States federal income tax purposes as a
redemption of notes of that series prior to maturity in exchange for the
property deposited in trust. In

S-6

that event, each holder would generally recognize, at the time of discharge,
gain or loss for United States federal income tax purposes measured by the
difference between (1) the sum of (a) the amount of any cash and (b) the fair
market value of any property deposited in trust deemed received by such holder
(unless attributable to accrued interest) and (2) such holder’s tax basis in the
notes of that series deemed surrendered. After the discharge, each such holder
would likely be treated as if it held an undivided interest in the cash (or
investments made therewith) and the property held in trust (or investments made
with interest received therefrom). Each such holder would generally be subject
to tax liability in respect of interest income and original issue discount, if
applicable, thereon and would recognize any gain or loss upon any disposition,
including redemption, of the assets held in trust. Although tax might be owed,
the holder of a discharged note would not receive cash (except for current
payments of interest on that note) until the maturity or earlier redemption (or,
if applicable, repurchase by us at the option of the holder) of that note.
United States federal income tax treatment of this nature could affect the
purchase price that a holder would receive upon the sale of the notes. You are
urged to consult with your tax advisor regarding the tax consequences of the
discharge of our obligations.

Book-Entry; Delivery and Form

The notes will be issued in the form of one or more global notes (“Global
Notes”) which will be held by the trustee as custodian for The Depository Trust
Company (the “Depositary”), New York, New York, and registered in the name of
Cede & Co., as nominee of the Depositary. All interests in the Global Notes
will be subject to the operations and procedures of the Depositary, Euroclear
Bank S.A./N.V. (“Euroclear”) and Clearstream Banking, soci t anonyme
(“Clearstream, Luxembourg”). The notes will be issued in fully registered form
without coupons and will be issued in, and beneficial interests in the Global
Notes must be held in, minimum denominations of $2,000 and integral multiples of
$1,000 in excess thereof.

Notwithstanding the foregoing, if (1) the Depositary notifies us that it is
unwilling or unable to continue as depositary for the notes of any series or if
the Depositary ceases to be eligible to act in such capacity and a successor
depositary is not appointed by us within 90 days, (2) an event or default (as
defined in the indenture) with respect to the notes of any series shall have
occurred and be continuing or (3) we in our sole discretion shall determine that
the notes of any series will no longer be represented by Global Notes, the
Global Notes of such series will be exchanged for notes of such series in
definitive form of like tenor and in an equal aggregate principal amount in
authorized denominations. Such definitive notes will be registered in such name
or names as the Depositary instructs the trustee.

The Depositary has advised us that pursuant to procedures established by it
(i) upon the issuance of the Global Notes, the Depositary or its custodian will
credit, on its internal system, the principal amount of the individual
beneficial interests represented by such Global Notes to the respective accounts
of persons who have accounts with such Depositary and (ii) ownership of
beneficial interests in the Global Notes will be shown on, and the transfer of
such ownership will be effected only through, records maintained by the
Depositary or its nominee (with respect to interests of participants) and the
records of participants (with respect to interests of persons other than
participants). Ownership of beneficial interests in the Global Notes will be
limited to persons who have accounts with the Depositary (“participants”) or
persons who hold interests through participants. Holders may hold their
interests in the Global Notes directly through the Depositary if they are
participants in such system, or indirectly through organizations that are
participants in such system.

So long as the Depositary, or its nominee, is the registered owner or holder
of the notes, the Depositary or such nominee, as the case may be, will be
considered the sole owner or holder of the notes represented by such Global
Notes for all purposes under the indenture. No beneficial owner of

S-7

an interest in the Global Notes will be able to transfer that interest except
in accordance with the Depositary’s procedures and those provided for under the
indenture.

Payments of the principal of and premium, if any, and interest on the Global
Notes will be made to the Depositary or its nominee, as the case may be, as the
registered owner of the Global Notes. Neither we nor the trustee or any paying
agent under the indenture will have any responsibility or liability for any
aspect of the records relating to or payments made on account of beneficial
ownership interests in the Global Notes or for maintaining, supervising or
reviewing any records relating to such beneficial ownership interests.

The Depositary has advised us that its present practice is, upon receipt of
any payment of principal of and premium, if any, and interest on the Global
Notes, to credit participants’ accounts immediately with payments in amounts
proportionate to their respective beneficial interests in the principal amount
of the Global Notes as shown on the records of the Depositary. Payments by
participants to owners of beneficial interests in the Global Notes held through
such participants will be governed by standing instructions and customary
practice, as is now the case with securities held for the accounts of customers
registered in the names of nominees for such customers. Such payments will be
the responsibility of such participants. Transfers between participants in the
Depositary will be effected in the ordinary way through the Depositary’s
same-day funds settlement system in accordance with the Depositary’s rules and
will be settled in same-day funds.

The Depositary has advised us as follows: the Depositary is a limited purpose
trust company organized under the laws of the State of New York, a member of the
Federal Reserve System, a “clearing corporation” within the meaning of the
Uniform Commercial Code and a “clearing agency” registered pursuant to the
provisions of Section 17A of the Securities Exchange Act of 1934. The Depositary
was created to hold securities for its participants and facilitate the clearance
and settlement of securities transactions between participants through
electronic book-entry changes in accounts of its participants, thereby
eliminating the need for physical movement of certificates. Participants include
securities brokers and dealers, banks, trust companies and clearing corporations
and certain other organizations. Indirect access to the Depositary system is
available to others such as banks, brokers, dealers and trust companies that
clear through or maintain a custodial relationship with a participant, either
directly or indirectly, or indirect participants.

Although the Depositary has agreed to the foregoing procedures in order to
facilitate transfers of interests in the Global Notes among participants of the
Depositary, it is under no obligation to perform such procedures, and such
procedures may be discontinued at any time. None of us, any of the underwriters
or the trustee will have any responsibility for the performance by the
Depositary or its participants or indirect participants of their respective
obligations under the rules and procedures governing their operations.

Clearstream, Luxembourg and Euroclear hold interests on behalf of their
participating organizations through customers’ securities accounts in
Clearstream, Luxembourg’s and Euroclear’s names on the books of their respective
depositaries, which hold those interests in customers’ securities accounts in
the depositaries’ names on the books of the Depositary. At the present time,
Citibank, N.A. acts as U.S. depositary for Clearstream, Luxembourg, and JPMorgan
Chase Bank, N.A. acts as U.S. depositary for Euroclear (the “U.S.
Depositaries”).

Clearstream, Luxembourg holds securities for its participating organizations
(“Clearstream Participants”) and facilitates the clearance and settlement of
securities transactions between Clearstream Participants through electronic
book-entry changes in accounts of Clearstream Participants, thereby eliminating
the need for physical movement of certificates. Clearstream, Luxembourg provides
to Clearstream Participants, among other things, services for safekeeping,
administration, clearance and settlement of internationally traded securities
and securities lending and borrowing.

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Clearstream, Luxembourg is registered as a bank in Luxembourg, and as such is
subject to regulation by the Commission de Surveillance du Secteur Financier and
the Banque Centrale du Luxembourg, which supervise and oversee the activities of
Luxembourg banks. Clearstream Participants are financial institutions including
investment banks, securities brokers and dealers, banks, trust companies and
clearing corporations, and may include the underwriters or their affiliates.
Indirect access to Clearstream, Luxembourg is available to other institutions
that clear through or maintain a custodial relationship with a Clearstream
Participant. Clearstream, Luxembourg has established an electronic bridge with
Euroclear as the operator of the Euroclear System (the “Euroclear Operator”) in
Brussels to facilitate settlement of trades between Clearstream, Luxembourg and
the Euroclear Operator.

Distributions with respect to the notes held beneficially through
Clearstream, Luxembourg will be credited to cash accounts of Clearstream
Participants in accordance with its rules and procedures, to the extent received
by the U.S. Depositary for Clearstream, Luxembourg.

Euroclear holds securities and book-entry interests in securities for
participating organizations (“Euroclear Participants”) and facilitates the
clearance and settlement of securities transactions between Euroclear
Participants, and between Euroclear Participants and participants of certain
other securities intermediaries through electronic book-entry changes in
accounts of such participants or other securities intermediaries. Euroclear
provides Euroclear Participants, among other things, with safekeeping,
administration, clearance and settlement, securities lending and borrowing, and
related services. Euroclear Participants are investment banks, securities
brokers and dealers, banks, central banks, supranationals, custodians,
investment managers, corporations, trust companies and certain other
organizations, and may include the underwriters or their affiliates.
Non-participants in Euroclear may hold and transfer beneficial interests in a
Global Note through accounts with a participant in the Euroclear System or any
other securities intermediary that holds a book-entry interest in a Global Note
through one or more securities intermediaries standing between such other
securities intermediary and Euroclear.

Securities clearance accounts and cash accounts with the Euroclear Operator
are governed by the Terms and Conditions Governing Use of Euroclear and the
related Operating Procedures of the Euroclear System, and applicable Belgian law
(collectively, the “Terms and Conditions”). The Terms and Conditions govern
transfers of securities and cash within Euroclear, withdrawals of securities and
cash from Euroclear and receipts of payments with respect to securities in
Euroclear. All securities in Euroclear are held on a fungible basis without
attribution of specific certificates to specific securities clearance accounts.
The Euroclear Operator acts under the Terms and Conditions only on behalf of
Euroclear Participants, and has no record of or relationship with persons
holding through Euroclear Participants.

Distributions on the notes held beneficially through Euroclear will be
credited to the cash accounts of Euroclear Participants in accordance with the
Terms and Conditions, to the extent received by the U.S. Depositary for
Euroclear.

Transfers between Euroclear Participants and Clearstream Participants will be
effected in the ordinary way in accordance with their respective rules and
operating procedures.

Cross-market transfers between direct participants in the Depositary, on the
one hand, and Euroclear Participants or Clearstream Participants, on the other
hand, will be effected through the Depositary in accordance with the
Depositary’s rules on behalf of Euroclear or Clearstream, Luxembourg, as the
case may be, by its U.S. Depositary; however, such cross-market transactions
will require delivery of instructions to Euroclear or Clearstream, Luxembourg,
as the case may be, by the counterparty in such system in accordance with the
rules and procedures and within the established deadlines (European time) of
such system. Euroclear or Clearstream, Luxembourg, as the case may be, will, if
the transaction meets its settlement requirements, deliver instructions to its
U.S. Depositary to

S-9

take action to effect final settlement on its behalf by delivering or
receiving interests in the Global Notes in the Depositary, and making or
receiving payment in accordance with normal procedures for same-day fund
settlement applicable to the Depositary. Euroclear Participants and Clearstream
Participants may not deliver instructions directly to their respective U.S.
Depositaries.

Due to time zone differences, the securities accounts of a Euroclear
Participant or Clearstream Participant purchasing an interest in a Global Note
from a direct participant in the Depositary will be credited, and any such
crediting will be reported to the relevant Euroclear Participant or Clearstream
Participant, during the securities settlement processing day (which must be a
business day for Euroclear or Clearstream, Luxembourg) immediately following the
settlement date of the Depositary. Cash received in Euroclear or Clearstream,
Luxembourg as a result of sales of interests in a Global Note by or through a
Euroclear Participant or Clearstream Participant to a direct participant in the
Depositary will be received with value on the settlement date of the Depositary
but will be available in the relevant Euroclear or Clearstream, Luxembourg cash
account only as of the business day for Euroclear or Clearstream, Luxembourg
following the Depositary’s settlement date.

The information in this section concerning the Depositary, Euroclear and
Clearstream, Luxembourg and their book-entry systems has been obtained from
sources that we believe to be reliable, but we take no responsibility for the
accuracy of that information.

Although Euroclear and Clearstream, Luxembourg have agreed to the foregoing
procedures to facilitate transfers of interests in the Global Notes among
Euroclear Participants and Clearstream Participants, they are under no
obligation to perform or to continue to perform such procedures, and such
procedures may be discontinued at any time. None of us, any of the underwriters
or the trustee will have any responsibility for the performance by Euroclear or
Clearstream, Luxembourg or their respective Participants of their respective
obligations under the rules and procedures governing their operations.

S-10

CERTAIN UNITED STATES FEDERAL INCOME TAX CONSEQUENCES

TO NON-U.S. HOLDERS

The following is a summary of certain United States federal income tax
consequences of the purchase, ownership, and disposition of the notes by an
initial purchaser of the notes that, for United States federal income tax
purposes, is not a “United States person” as defined below (a “Non-U.S. Holder”)
and purchases the notes pursuant to this prospectus supplement. This summary is
based upon existing United States federal income tax law, which is subject to
differing interpretations or change, possibly with retroactive effect. This
summary does not discuss all aspects of United States federal income taxation
which may be important to particular investors in light of their individual
investment circumstances, such as notes held by investors subject to special tax
rules (e.g., banks, financial institutions, insurance companies, broker-
dealers, partnerships and their partners, and tax-exempt organizations
(including private foundations)) or to persons that will hold the notes as part
of a straddle, hedge, conversion, constructive sale, or other integrated
security transaction for United States federal income tax purposes, all of whom
may be subject to tax rules that differ significantly from those summarized
below. In addition, this summary does not discuss any (i) United States federal
income tax consequences to a Non-U.S. Holder that (A) is engaged in the conduct
of a United States trade or business, (B) is a nonresident alien individual and
such holder is present in the United States for 183 or more days during the
taxable year, or (C) is a corporation which operates through a United States
branch, and (ii) state, local or non-United States tax considerations. Each
prospective investor is urged to consult its tax advisor regarding the United
States federal, state, local, and non-United States income and other tax
considerations of the purchase, ownership, and disposition of the notes.

For the purposes of this summary, a “United States person” is, for United
States federal income tax purposes, (i) a citizen or resident of the United
States, (ii) a corporation (or other entity classified as a corporation for
United States Federal income tax purposes) created or organized in or under the
law of, the United States or any State or the District of Columbia, (iii) an
estate the income of which is includible in gross income for United States
federal income tax purposes regardless of its source, or (iv) a trust (A) the
administration of which is subject to the primary supervision of a United States
court and which has one or more United States persons who have the authority to
control all substantial decisions of the trust or (B) that has otherwise validly
elected to be treated as a United States person.

Interest Income

Payments of interest on the notes made to a Non-U.S. Holder will not be
subject to United States federal income or withholding tax provided that (i)
such holder (A) does not actually or constructively own 10% or more of the total
combined voting power of all classes of our stock entitled to vote and (B) is
not a controlled foreign corporation that is related to us through stock
ownership for United States federal income tax purposes and (ii) the
requirements of section 871(h) or 881(c) of the Internal Revenue Code of 1986,
as amended (the “Code”), are satisfied as described below under the heading
“Owner’s Statement Requirement.”

Sale or Exchange

A Non-U.S. Holder generally will not be subject to United States federal
income tax on gain recognized on a sale, exchange, redemption, or other
disposition of a note.

Owner’s Statement Requirement

In order to avoid withholding tax on interest under section 871(h) or 881(c)
of the Code, either the beneficial owner of a note or a securities clearing
organization, bank or other financial institution that holds customers’
securities in the ordinary course of its trade or business (a “Financial

S-11

Institution”) and that holds a note on behalf of such owner must file a
statement with us or our agent to the effect that the beneficial owner is not a
United States person. This requirement will be satisfied if we or our agent
receives (i) a statement (an “Owner’s Statement”) from the beneficial owner of a
note in which such owner certifies, under penalties of perjury, that such owner
is not a United States person and provides such owner’s name and address, and if
applicable, information with respect to tax treaty benefits, on an Internal
Revenue Service Form W-8BEN (or suitable substitute form) or (ii) a statement
from the Financial Institution holding the note on behalf of the beneficial
owner in which the Financial Institution certifies, under penalties of perjury,
that it has received the Owner’s Statement, together with a copy of the Owner’s
Statement. The beneficial owner must inform us or our agent (or, in the case of
a statement described in clause (ii) of the immediately preceding sentence, the
Financial Institution) within 30 days of any change in information on the
Owner’s Statement.

Backup Withholding and Information Reporting

In general, a Non-U.S. Holder will not be subject to backup withholding or
information reporting with respect to payments of interest and proceeds from the
sale or other disposition of notes, if an Owner’s Statement or similar
documentation is received or an exemption has otherwise been established,
provided that the relevant agent does not know or have reason to know that the
payee is a United States person. If a note is held by a Non-U.S. Holder through
a United States or United States related broker or financial institution and, in
such case, if the Non-U.S. Holder fails to provide an Owner’s Statement or other
appropriate evidence of non-United States status, backup withholding may apply.

Backup withholding is not an additional tax. Any amount withheld under the
backup withholding rules from a payment to a Non-U.S. Holder may be refunded or
credited against the Non-U.S. Holder’s United States federal income tax
liability if the Non-U.S. Holder provides the required information to the United
States Internal Revenue Service.

S-12

UNDERWRITING

We and the underwriters named below have entered into an underwriting
agreement with respect to the notes. Subject to certain conditions, each
underwriter has severally agreed to purchase the principal amount of the notes
indicated in the following table.

The underwriters are committed, subject to certain conditions, to take and,
if any are taken, pay for all of the notes being offered.

Notes sold by the underwriters to the public will initially be offered at the
respective initial public offering prices set forth on the cover of this
prospectus supplement. Any notes sold by the underwriters to securities dealers
may be sold at a discount from the initial public offering prices of up to % of
the principal amount of the 20 notes and up to % of the principal amount of the
20 notes. Any such securities dealers may resell notes purchased from the
underwriters to certain other brokers or dealers at a discount from the initial
public offering prices of up to % of the principal amount of the 20 notes and up
to % of the principal amount of the 20 notes. If all the notes of any series are
not sold at the initial offering prices, the underwriters may change the
offering prices to the public and the other selling terms of the notes of such
series. The offering of the notes by the underwriters is subject to receipt and
acceptance and subject to the underwriters’ right to reject any order in whole
or in part.

The following table shows the underwriting discounts that we are to pay to
the underwriters in connection with this offering:

The notes of each series are a new issue of securities with no established
trading market. We have been advised by the underwriters that the underwriters
intend to make a market in each series of notes but they are not obligated to do
so and may discontinue market making at any time without notice. No assurance
can be given as to whether a trading market for any series of notes will develop
or as to the liquidity of any trading market for any series of notes that may
develop.

In connection with the offering, the underwriters may purchase and sell notes
in the open market. These transactions may include short sales, stabilizing
transactions and purchases to cover positions created by short sales. Short
sales involve the sale by the underwriters of a greater number of notes than
they are required to purchase in the offering. Stabilizing transactions consist
of certain bids or purchases made for the purpose of preventing or retarding a
decline in the market prices of the notes while the offering is in progress.

The underwriters also may impose a penalty bid. This occurs when a particular
underwriter repays to the underwriters a portion of the underwriting discount
received by it because the underwriting syndicate has repurchased notes sold by
or for the account of such underwriter in stabilizing or short covering
transactions.

These activities by the underwriters, as well as other purchases by the
underwriters for their own accounts, may stabilize, maintain or otherwise affect
the market prices of the notes. As a result, the prices of the notes may be
higher than the prices that otherwise might exist in the open market. If

S-13

these activities are commenced, they may be discontinued by the underwriters
at any time without notice. These transactions may be effected in the
over-the-counter market or otherwise.

We estimate that our share of the total expenses of the offering, excluding
underwriting discounts and commissions, will be approximately $ .

We have agreed to indemnify the several underwriters against certain
liabilities, including liabilities under the Securities Act of 1933.

In the ordinary course of their respective businesses, the underwriters and
their respective affiliates have engaged, and may in the future engage, in
commercial banking and investment banking transactions with us and our
affiliates, for which they have received and in the future may receive
compensation.

European Economic Area

In relation to each Member State of the European Economic Area which has
implemented the Prospectus Directive (each, a Relevant Member State), each
underwriter has represented and agreed that with effect from and including the
date on which the Prospectus Directive is implemented in that Relevant Member
State (the Relevant Implementation Date) it has not made and will not make an
offer of notes to the public in that Relevant Member State other than:

a.

to any legal entity which is a qualified investor as defined in the
Prospectus Directive;

b.

to fewer than 100 or, if the Relevant Member State has implemented the
relevant provision of the 2010 PD Amending Directive, 150, natural or legal
persons (other than qualified investors as defined in the Prospectus Directive),
as permitted under the Prospectus Directive, subject to obtaining the prior
consent of the representatives of the underwriters for any such offer; or

c.

in any other circumstances fully within Article 3(2) of the Prospectus
Directive,

provided that no such offer of notes shall requires us or any underwriter to
publish a prospectus pursuant to Article 3 of the Prospectus Directive or
supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

For the purposes of this provision, the expression an “offer of notes to the
public” in relation to any notes in any Relevant Member State means the
communication in any form and by any means of sufficient information on the
terms of the offer and the notes to be offered so as to enable an investor to
decide to purchase or subscribe the notes, as the same may be varied in that
Member State by any measure implementing the Prospectus Directive in that Member
State and the expression “Prospectus Directive” means Directive 2003/71/EC (and
amendments thereto, including the 2010 PD Amending Directive, to the extent
implemented in the Relevant Member State), and includes any relevant
implementing measure in each Relevant Member State and the expression “2010 PD
Amending Directive” means Directive 2010/73/EU.

United Kingdom

Each underwriter has represented and agreed that:

a.

it has only communicated or caused to be communicated and will only
communicate or cause to be communicated an invitation or inducement to engage in
investment activity (within the meaning of Section 21 of the Financial Services
and Markets Act 2000, as amended (“FSMA”)) received by it in connection with the
issue or sale of the notes in circumstances in which Section 21(1) of the FSMA
would not apply to us; and

b.

it has complied and will comply with all applicable provisions of the FSMA
with respect to anything done by it in relation to the notes in, from or
otherwise involving the United Kingdom.

S-14

LEGAL MATTERS

Certain legal matters in connection with the offering of the notes will be
passed upon for us by Kendrick F. Royer, our Assistant General Counsel. Certain
matters relating to federal income tax considerations will be passed upon for us
by Skadden, Arps, Slate, Meagher & Flom LLP, Los Angeles, California. Sidley
Austin LLP, San Francisco, California, will act as counsel to the underwriters.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other
information with the Securities and Exchange Commission, or SEC. You may read
and copy any document we file at the SEC’s Public Reference Room at 100 F
Street, N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at
1-800-SEC-0330 for further information on the Public Reference Room. The SEC
also maintains a website at www.sec.gov that contains reports, proxy
statements and other information regarding issuers that file electronically with
the SEC, including us. These reports, proxy statements and other information can
also be read through the Investor Relations section of our website at
www.oxy.com. Information on our website does not constitute part of,
and is not incorporated by reference in, this prospectus supplement or the
accompanying prospectus and should not be relied upon in connection with making
any investment decision with respect to the notes.

The SEC allows us to “incorporate by reference” the information that we file
with the SEC. This permits us to disclose important information to you by
referencing these filed documents. Any information referenced this way is
considered part of this prospectus supplement, and any information filed with
the SEC subsequent to the date of this prospectus supplement will automatically
be deemed to update and supersede this information. We incorporate by reference
the following documents (except for “furnished” information described below)
which have been filed with the SEC:

Annual Report on Form 10-K for the year ended December 31, 2010;

Quarterly Reports on Form 10-Q for the quarters ended March 31, 2011 and June
30, 2011; and

Current Reports on Form 8-K filed on January 20, 2011, January 26, 2011,
April 28, 2011, May 6, 2011, May 10, 2011, July 18, 2011 and July 26, 2011.

We also incorporate by reference all documents we may subsequently file with
the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities
Exchange Act of 1934 after the date of this prospectus supplement until the
termination of the offering.

Information furnished under Items 2.02 or 7.01 (or corresponding information
furnished under Item 9.01 or included as an exhibit) in any past or future
Current Report on Form 8-K (including the Current Reports on Form 8-K listed
above) that we file with the SEC, unless otherwise expressly specified in such
report, is not incorporated by reference in this prospectus supplement.

We will provide without charge upon written or oral request, a copy of any or
all of the documents which are incorporated by reference into this prospectus
supplement. Requests should be directed to:

Occidental Petroleum Corporation
10889 Wilshire Boulevard
Los Angeles, California 90024
Attn: Robert J. Williams
Telephone: (310) 208-8800

You should rely only on the information contained or incorporated by
reference in this prospectus supplement and the accompanying prospectus and any
applicable free writing prospectuses. We have not authorized any person to
provide you with different information. If anyone provides you with different or
inconsistent information, you should not rely on it. We are not making an offer
to sell

S-15

these securities in any jurisdiction where the offer or sale is not
permitted. The information contained in this prospectus supplement and the
accompanying prospectus is accurate only as of the respective dates on the front
covers of this prospectus supplement and the accompanying prospectus, the
information contained in any related free writing prospectus will be accurate
only as of the date of that document, and the information contained in any
document incorporated by reference in this prospectus supplement is accurate
only as the date of such document. Our business, financial condition, results of
operations and prospects may have changed since those respective dates.

Except as provided above, no other information, including information on our
internet site, is incorporated by reference in this prospectus supplement, the
accompanying prospectus or any free writing prospectus.

S-16

Prospectus

OCCIDENTAL PETROLEUM CORPORATION

Senior Debt Securities

We may offer, issue and sell senior debt securities from time to time.

We may offer and sell these senior debt securities to or through one or more
underwriters, dealers and agents, or directly to purchasers, on a continuous or
delayed basis.

This prospectus describes some of the general terms that may apply to these
senior debt securities. The specific terms of any senior debt securities to be
offered will be described in a supplement to this prospectus. The prospectus
supplement may also add, update or change information contained in this
prospectus. You should read this prospectus and the applicable prospectus
supplement carefully before you make your investment decision.

Investing in our senior debt securities involves risks. See “Risk
Factors” in our most recent annual report on Form 10-K, which is incorporated
herein by reference, in any of our subsequently filed quarterly and current
reports that are incorporated herein by reference and in any applicable
prospectus supplement.

This prospectus may not be used to sell senior debt securities unless
accompanied by a prospectus supplement.

Neither the Securities and Exchange Commission nor any state
securities commission has approved or disapproved of these securities or
determined if this prospectus or the accompanying prospectus supplement is
truthful or complete. Any representation to the contrary is a criminal
offense.

The date of this prospectus is August 15, 2011.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

Unless otherwise stated or the context otherwise requires, the terms
“Occidental,” “we,” “us” and “our” refer to Occidental Petroleum Corporation and
not any of its subsidiaries.

This prospectus is part of a registration statement we filed with the
Securities and Exchange Commission (the “SEC”) using a “shelf” registration
process. Under this shelf registration process, we may from time to time sell
the senior debt securities described in this prospectus in one or more
offerings.

This prospectus describes some of the general terms that may apply to these
senior debt securities. The specific terms of any senior debt securities to be
offered will be described in a supplement to this prospectus. The prospectus
supplement may also add, update or change information contained in this
prospectus. You should read carefully this prospectus and the applicable
prospectus supplement together with any additional information described under
the heading “Where You Can Find More Information” before you make your
investment decision.

RISK FACTORS

Investing in our senior debt securities involves risks. You should
carefully consider the risk factors incorporated by reference in this prospectus
and included in any accompanying prospectus supplement. Specifically, please see
“Risk Factors” included in our Annual Report on Form 10-K for the year ended
December 31, 2010 and the other information in that and the other reports that
we file with the SEC that are incorporated by reference in this prospectus for a
discussion of risk factors that may affect our business. Realization of any of
those risks or the risks disclosed in any accompanying prospectus supplement or
adverse results from any matter listed under the heading “Forward-Looking
Statements” in this prospectus, in any accompanying prospectus supplement or in
any such reports could have a material adverse effect on our business, financial
condition, cash flows and results of operations, and you might lose all or part
of your investment.

FORWARD-LOOKING STATEMENTS

This prospectus, any accompanying prospectus supplement and the documents
incorporated by reference herein and therein contain forward-looking statements
and involve risks and uncertainties that could materially affect expected
results of operations, liquidity, cash flows and business prospects. Factors
that could cause results to differ materially include, but are not limited to:

global commodity pricing fluctuations;

international political conditions;

general domestic political conditions, including permitting;

supply and demand considerations for our products;

not successfully completing, or any material delay of, any development of new
fields, expansion projects, capital expenditures, efficiency-improvement
projects, acquisitions or dispositions;

failure to achieve expected production from existing and future oil and gas
development projects or acquisitions

exploration risks such as drilling unsuccessful wells;

any general economic recession or slowdown domestically or internationally;

higher-than-expected costs;

liability for remedial actions under existing or future environmental
regulations and litigation;

liability resulting from pending or future litigation;

potential disruption or interruption of our production or manufacturing
facilities due to accidents, chemical releases, labor unrest, weather, natural
disasters, political events or insurgent activity;

changes in law or regulations; and

changes in tax law or regulations.

Words such as “estimate,” “project,” “predict,” “will,” “would,” “should,”
“could,” “may,” “might,” “anticipate,” “aim,” “goal,” “target,” “objective,”
“plan,” “intend,” “believe,” “expect” or similar expressions that convey the
uncertainty of future events or outcomes generally indicate forward-looking
statements. You should not place undue reliance on these forward-looking
statements, which speak only as of the date of this prospectus or, in the case
of documents incorporated by reference, as of the date of those documents.
Unless legally required, we do not undertake any obligation to update any
forward-looking statements, as a result of new information, future events or
otherwise. Certain risks

1

that may affect our results of operations and financial position appear under
the heading “Risk Factors” and elsewhere in our most recent annual report on
Form 10-K, which is incorporated herein by reference, as well as in any of our
subsequently filed quarterly or current reports that are incorporated herein by
reference and any applicable prospectus supplement.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other
information with the SEC. You may read and copy any document we file at the
SEC’s Public Reference Room at 100 F Street, N.E., Room 1580, Washington, D.C.
20549. Please call the SEC at 1-800-SEC-0330 for further information on the
Public Reference Room. The SEC also maintains a website at www.sec.gov
that contains reports, proxy statements and other information regarding issuers
that file electronically with the SEC, including us. These reports, proxy
statements and other information can also be read through the Investor Relations
section of our website at www.oxy.com. Information on our website does
not constitute part of, and is not incorporated by reference in, this prospectus
and should not be relied upon in connection with making any investment decision
with respect to our securities.

The SEC allows us to “incorporate by reference” the information that we file
with the SEC. This permits us to disclose important information to you by
referencing these filed documents. Any information referenced this way is
considered part of this prospectus, and any information filed with the SEC
subsequent to the date of this prospectus, or contained in any accompanying
prospectus supplement or related free-writing prospectus, will automatically be
deemed to update and supersede this information. We incorporate by reference the
following documents (except for “furnished” information described below) which
have been filed with the SEC:

Annual Report on Form 10-K for the year ended December 31, 2010;

Quarterly Reports on Form 10-Q for the quarters ended March 31, 2011 and June
30, 2011; and

Current Reports on Form 8-K filed on January 20, 2011, January 26, 2011,
April 28, 2011, May 6, 2011, May 10, 2011, July 18, 2011 and July 26, 2011.

We also incorporate by reference all documents we may subsequently file with
the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities
Exchange Act of 1934 after the initial filing date of the registration statement
of which this prospectus is a part and prior to the termination of the offering.

Information furnished under Items 2.02 or 7.01 (or corresponding information
furnished under Item 9.01 or included as an exhibit) in any past or future
Current Report on Form 8-K (including the Current Reports on Form 8-K listed
above) that we file with the SEC, unless otherwise expressly specified in such
report, is not incorporated by reference in this prospectus.

We will provide without charge upon written or oral request, a copy of any or
all of the documents which are incorporated by reference into this prospectus.
Requests should be directed to:

Occidental Petroleum Corporation
10889 Wilshire Boulevard
Los Angeles, California 90024
Attn: Robert J. Williams
Telephone: (310) 208-8800

You should rely only on the information contained or incorporated by
reference in this prospectus and any accompanying prospectus supplements and any
applicable free writing prospectuses. We have not authorized any other person to
provide you with different information. If anyone provides you with different or
inconsistent information, you should not rely on it. We are not making an offer
to sell these securities in any jurisdiction where the offer or sale is not
permitted. The information contained

2

in this prospectus is accurate only as of the date on the front cover of this
prospectus, the information contained in any accompanying prospectus supplement
or related free writing prospectus will be accurate only as of the date of that
document, and the information contained in any document incorporated by
reference in this prospectus is accurate only as the date of such document. Our
business, financial condition, results of operations and prospects may have
changed since that date.

Except as provided above, no other information, including information on our
internet site, is incorporated by reference in this prospectus.

OCCIDENTAL

Our principal businesses consist of three segments operated by our
subsidiaries and affiliates. The oil and gas segment explores for, develops,
produces and markets crude oil, including natural gas liquids (NGLs) and
condensate (together with NGLs, “liquids”), as well as natural gas. The chemical
segment manufactures and markets basic chemicals, vinyls and other chemicals.
The midstream, marketing and other segment gathers, treats, processes,
transports, stores, purchases and markets crude oil, liquids, natural gas,
carbon dioxide and power. It also trades around its assets, including pipelines
and storage capacity, and trades oil and gas, other commodities and
commodity-related securities. Our principal executive offices are located at
10889 Wilshire Boulevard, Los Angeles, California 90024; telephone (310)
208-8800.

3

USE OF PROCEEDS

Unless we inform you otherwise in a prospectus supplement, the net proceeds
we receive from the sale of senior debt securities, if any, offered under this
prospectus may be used for general corporate purposes, including working
capital, acquisitions, retirement of debt, stock repurchases and other business
opportunities.

DESCRIPTION OF SENIOR DEBT SECURITIES

General

We may issue one or more series of senior debt securities pursuant to this
prospectus. We may issue the senior debt securities under an indenture (the
“Senior Indenture”) to be entered into between us and The Bank of New York
Mellon Trust Company, N.A., as trustee (“Senior Indenture Trustee”). The form of
Senior Indenture is included as an exhibit to the registration statement of
which this prospectus is a part.

Below is a description of certain general terms of the senior debt
securities. The description is not complete and is subject to and qualified in
its entirety by reference to the Senior Indenture. The particular terms of a
series of senior debt securities will be described in a prospectus supplement
and, if applicable, a pricing supplement. Capitalized terms used but not defined
in this summary have the meanings specified in the Senior Indenture.

The senior debt securities will rank equally with all of our unsecured and
unsubordinated debt. The Senior Indenture is subject to the Trust Indenture Act
of 1939, as amended (the “Trust Indenture Act”). The Senior Indenture does not
limit the amount of senior debt securities which we may issue, nor does it limit
us or our subsidiaries from issuing any other unsecured debt. Such other
unsecured debt may have different terms than the senior debt securities. Our
previously issued and outstanding senior debt does have different terms than the
senior debt securities (including different restrictive covenants and event of
default provisions). The terms of the senior debt securities issued under this
prospectus will only be as described in the Senior Indenture, this prospectus
and any prospectus supplement.

Each prospectus supplement, together with a pricing supplement, if
applicable, will describe the terms relating to a series of senior debt
securities, which may include:

the title;

any limit on the amount that may be issued (unless expressly provided in the
applicable prospectus supplement or pricing supplement, a series of our senior
debt securities may be re-opened from time to time for the issuance of
additional senior debt securities of that series subject to any terms and
conditions set forth in or established pursuant to the Senior Indenture);

whether or not that series of senior debt securities will be issued as
registered securities, bearer securities or both;

the price at which that series of senior debt securities will be issued,
which may be at a discount;

whether or not that series of senior debt securities will be issued in global
form and, if applicable, who the depositary will be;

the maturity date(s) or the method of determining the maturity date(s);

the person to whom any interest will be payable on any registered security,
if other than the person in whose name that security is registered at the close
of business on the regular record date;

4

the interest rate(s), if any, (which may be fixed or variable) or the method
for determining the rate(s) and the date(s) interest will begin to accrue, the
date(s) interest will be payable and the regular record date(s) for interest
payment date(s);

the place(s) where payments shall be payable, registered securities may be
surrendered for registration of transfer, securities may be surrendered for
exchange, and notices and demands to or upon us may be served;

the period(s) within which, and the price(s) at which, that series of senior
debt securities may, pursuant to any optional or mandatory redemption
provisions, be redeemed, in whole or in part, and other related terms and
conditions;

any mandatory or optional sinking fund provisions or any provisions for
remarketing that series of senior debt securities and other related terms and
provisions;

the denominations in which that series of senior debt securities will be
issued, if other than denominations of $1,000 in the case of registered
securities and any integral multiple thereof, and in the case of bearer
securities, if other than denominations of $5,000 and $100,000;

the currency or currencies, including composite currencies or currency units,
in which that series of senior debt securities may be denominated or in which
payment of the principal of and interest, if any, on that series of senior debt
securities shall be payable, if other than the currency of the United States of
America, and, if so, whether that series of senior debt securities may be
satisfied and discharged other than as provided in Article Four of the Senior
Indenture;

if the amounts of payments of principal of and interest on, if any, that
series of senior debt securities are to be determined by reference to an index,
formula or other method, or based on a coin or currency other than that in which
that series of senior debt securities are stated to be payable, the manner in
which such amounts shall be determined and the calculation agent, if any, with
respect thereto;

if other than the principal amount thereof, the portion of the principal
amount of that series of senior debt securities that will be payable upon
declaration of acceleration of the maturity thereof pursuant to an event of
default;

whether we will pay additional amounts on any of the senior debt securities
and coupons, if any, of the series to any non-United States holder in respect of
any tax, assessment or governmental charge withheld or deducted, and under what
circumstances and with what procedures we will pay such additional amounts;

if other than as defined in the Senior Indenture, the meaning of “Business
Day” when used with respect to that series of senior debt securities;

if that series of senior debt securities may be issued or delivered (whether
upon original issuance or upon exchange of a temporary security of such series
or otherwise), or any installment of principal or interest is payable, only upon
receipt of certain certificates or other documents or satisfaction of other
conditions in addition to those specified in the Senior Indenture, the forms and
terms of those certificates, documents or conditions;

any addition to, or modification or deletion of, any event of default,
covenant or other term or provision specified in the Senior Indenture with
respect to that series of senior debt securities; and

any other terms, which other terms may, subject, in the case of an existing
outstanding series of senior debt securities, to the provisions of the Senior
Indenture described below under “:Modification of Senior Indenture; Waiver,”
amend, supplement or replace any of the terms of the Senior Indenture insofar as
it concerns the senior debt securities of that series.

5

Each prospectus supplement or pricing supplement, as applicable, may describe
certain United States federal income tax considerations applicable to the
purchase, holding and disposition of the senior debt securities that the
prospectus supplement or pricing supplement covers, as applicable.

Limitation on Liens

We will not, nor will we permit any Consolidated Subsidiary (as defined
below) to, incur, create, assume, guarantee or otherwise become liable with
respect to any Secured Debt (as defined below), unless the senior debt
securities are secured equally and ratably with (or prior to) such Secured Debt.
This covenant will not apply to:

(1) Liens (as defined below) existing on the date of the Senior Indenture;

(2) Liens existing on property of, or on any shares of Capital Stock or
Indebtedness (each as defined below) of, any Business Entity at the time such
Business Entity becomes a Consolidated Subsidiary or at the time such Business
Entity is merged into or consolidated with us or any Consolidated Subsidiary or
at the time of sale, lease or other disposition of the properties of such
Business Entity (or a division of such Business Entity) to us or a Consolidated
Subsidiary as an entirety or substantially as an entirety;

(3) Liens in favor of us or a Consolidated Subsidiary;

(4) Liens in favor of governmental bodies to secure progress, advance or
other payments pursuant to any contract or provision of any statute;

(5) Liens existing on property, shares of Capital Stock or Indebtedness at
the time of acquisition thereof (including acquisition through merger or
consolidation) or Liens to (i) secure the payment of all or any part of the
purchase price thereof or the cost of construction, installation, expansion,
renovation, improvement or development on or of such property or (ii) secure any
Indebtedness incurred prior to, at the time of, or within two years after the
later of the acquisition, the completion of such construction, installation,
expansion, renovation, improvement or development or the commencement of full
operation of such property or within two years after the acquisition of such
shares or Indebtedness for the purpose of financing all or any part of the
purchase price or cost thereof;

(6) Liens on any specific oil or gas property to secure Indebtedness incurred
by us or any Consolidated Subsidiary to provide funds for all or any portion of
the cost of exploration, production, gathering, processing, marketing, drilling
or development of such property;

(7) Liens on any Principal Domestic Property securing Indebtedness incurred
under industrial development, pollution control or other revenue bonds issued or
guaranteed by the United States of America or any State thereof or any
department, agency, instrumentality or political subdivision of either;

(8) Liens on any Principal Domestic Property securing Indebtedness arising in
connection with the sale of accounts receivable resulting from the sale of oil
or gas at the wellhead; and

(9) certain extensions, renewals or refundings of any Liens referred to in
the foregoing clauses (1) through (8).

Notwithstanding the foregoing, we and one or more Consolidated Subsidiaries
may incur, create, assume, guarantee or otherwise become liable with respect to
any Secured Debt that would otherwise be subject to the foregoing restrictions
if, after giving effect thereto, the aggregate amount of all Secured Debt,
together with the Discounted Rental Value (as defined below) in respect of sale
and leaseback transactions involving Principal Domestic Properties (excluding
sale and leaseback transactions exempted from the restrictions discussed below
under the caption “:Limitations on Sale

6

and Leaseback Transactions” pursuant to clause (1) or (2) of the second
paragraph under such caption), would not exceed 15% of Consolidated Net Tangible
Assets (as defined below).

Limitations on Sale and Leaseback Transactions

We will not, nor will we permit any Consolidated Subsidiary to, sell or
transfer any Principal Domestic Property (as defined below), with us or any
Consolidated Subsidiary taking back a lease of such Principal Domestic Property,
unless:

(1) such Principal Domestic Property is sold within 360 days after the later
of the date of acquisition, completion of construction or commencement of full
operations of such Principal Domestic Property;

(2) we or such Consolidated Subsidiary could subject such Principal Domestic
Property to a Lien securing Indebtedness pursuant to the provisions described
above under “:Limitation on Liens” in an amount equal to the Discounted Rental
Value with respect to the lease entered into in connection with such sale and
leaseback transaction without equally and ratably securing the senior debt
securities; or

(3) we or such Consolidated Subsidiary, within 360 days after such sale,
applies or causes to be applied to the retirement of our or its Funded Debt (as
defined below) an amount not less than the greater of (a) the net proceeds of
the sale of the Principal Domestic Property leased pursuant to such sale and
leaseback transaction or (b) the fair value (as determined in any manner
approved by our Board of Directors) of the Principal Domestic Property so leased
(provided, however, that the amount applied to the retirement of Funded Debt
shall be reduced by the principal amount of Funded Debt of us or such
Consolidated Subsidiary voluntarily retired by us or such Consolidated
Subsidiary within 360 days after such sale).

This restriction will not apply to any sale and leaseback transaction (1)
between us and a Consolidated Subsidiary or between Consolidated Subsidiaries or
(2) involving the sale or transfer of any Principal Domestic Property with a
lease for a period, including renewals, of not more than 36 months.

Certain Definitions

“Business Entity” means a corporation, association, business trust,
partnership, limited liability company or other business entity.

“Capital Stock” means (a) in the case of a corporation, common stock,
preferred stock and any other capital stock, (b) in the case of a partnership,
partnership interests (whether general or limited), (c) in the case of a limited
liability company, limited liability company interests, and (d) in the case of
any other Business Entity, any other interest or participation that confers on a
Person the right to receive a share of the profits and losses of, or
distribution of assets of, such Business Entity, but excluding from all of the
foregoing any debt securities convertible into Capital Stock, whether or not
such debt securities include any right of participation with Capital Stock.

“Consolidated Net Tangible Assets” means the total of the Net Tangible Assets
of us and our Consolidated Subsidiaries, included in our and our Consolidated
Subsidiaries’ financial statements prepared on a consolidated basis in
accordance with United States generally accepted accounting principles, after
eliminating all intercompany items.

“Consolidated Subsidiary” means any Subsidiary included in our and our
Subsidiaries’ financial statements prepared on a consolidated basis in
accordance with United States generally accepted accounting principles.

“Current Liabilities” means all Indebtedness that may properly be classified
as current liabilities in accordance with United States generally accepted
accounting principles.

7

“Discounted Rental Value” means, as to any particular lease under which any
Person is at the time liable and at any date as of which the amount thereof is
to be determined, the total net amount of rent (after deducting the amount of
rent to be received by such Person under noncancelable subleases) required to be
paid by such Person under such lease during the remaining noncancelable term
thereof (including any such period for which such lease has been extended or
may, at the option of the lessor, be extended), discounted from the respective
due dates thereof to such date at a rate per annum of 11³/4%. The net
amount of rent required to be paid under any such lease for any such period
shall be the aggregate amount of the rent payable by the lessee with respect to
such period, after excluding amounts required to be paid on account of
maintenance and repairs, insurance, taxes, water rates and similar charges. In
the case of any lease which is terminable by the lessee upon the payment of a
penalty, such net amount shall also include the amount of such penalty, but no
rent shall be considered as required to be paid under such lease subsequent to
the first date upon which it may be so terminated. If and to the extent the
amount of any rent during any future period is not definitely determinable under
the lease in question, the amount of such rent shall be estimated in such
reasonable manner as our Board of Directors may in good faith determine.

“Funded Debt” means all Indebtedness maturing one year or more from the date
of the creation thereof, all Indebtedness directly or indirectly renewable or
extendible, at the option of the debtor, by its terms or by the terms of any
instrument or agreement relating thereto, to a date one year or more from the
date of the creation thereof, and all Indebtedness under a revolving credit or
similar agreement obligating the lender or lenders to extend credit over a
period of one year or more, even though such Indebtedness may also conform to
the definition of Short-Term Borrowing.

“Indebtedness,” as applied to a Person, means, as of the date on which
Indebtedness is to be determined (a) all items (except items of Capital Stock or
of surplus or of deferred credits or noncontrolling interest in Subsidiaries)
which, in accordance with United States generally accepted accounting principles
in effect from time to time, would be included in determining total liabilities,
as shown on the liability side of a balance sheet of such Person; (b) all
indebtedness secured by any mortgage on any property or asset owned or held by
such Person subject thereto, whether or not the indebtedness secured thereby has
been assumed; and (c) all indebtedness of others which such Person has directly
or indirectly guaranteed, endorsed (otherwise than for collection or deposit in
the ordinary course of business), discounted with recourse, agreed (contingently
or otherwise) to purchase or repurchase or otherwise acquire, or in respect of
which such Person has otherwise become directly or indirectly liable. For the
purpose of computing Indebtedness of any Person, there shall be excluded any
particular Indebtedness which meets one or more of the following categories:

(i) Indebtedness with respect to which sufficient cash or cash equivalents or
securities have been deposited in trust to provide for the full payment,
redemption or satisfaction of the principal of, premium, if any, and interest to
accrue on, such Indebtedness to the stated maturity thereof or to the date of
prepayment thereof, as the case may be, and, as a result of such deposit, such
particular Indebtedness, in accordance with United States generally accepted
accounting principles, is no longer required to be reported on a balance sheet
of such Person as a liability, and such cash or cash equivalents or securities
are not required to be reported as an asset;

(ii) Indebtedness which is not classified as Indebtedness under clause (a) of
this definition and which arises from any commitment of such Person relating to
pipeline operations to pay for property or services substantially without regard
to the non-delivery of such property or the non-furnishing of such services; or

(iii) Indebtedness which is not classified as Indebtedness under clause (a)
of this definition and which is payable solely out of certain property or assets
of such Person, or is secured by a mortgage on certain property or assets owned
or held by such Person, in either case without any further recourse to or
liability of such Person, to the extent such Indebtedness exceeds (x) if such

8

Person records such property or assets on its books, the value for such
property or assets recorded on such books or (y) if such Person does not record
such property or assets on its books, (1) if such Indebtedness is a general
obligation of the entity which does record such property or assets on its books,
the net investment in or advances to such entity as recorded on the books of
such Person or (2) if such Indebtedness is payable solely out of certain
property or assets of such entity, the lesser of the value for such property or
assets recorded on the books of such entity or the net investment in or advances
to such entity as recorded on the books of such Person, in each case determined
in accordance with United States generally accepted accounting principles.

“Lien” means and includes any mortgage, pledge, lien, security interest,
conditional sale or other title retention agreement or other similar encumbrance
to secure Indebtedness for borrowed money, but excluding (i) any security
interest which a lessor may be deemed to have under a lease and (ii) any lien
which may be deemed to exist under a Production Payment or under any
subordination arrangement.

“Net Tangible Assets” of any specified Person means the total of all assets
properly appearing on a balance sheet of such Person prepared in accordance with
United States generally accepted accounting principles, after deducting from
such total, without duplication of deductions, (a) all Current Liabilities of
such Person; (b) that portion of the book amount of all such assets which would
be treated as intangibles under United States generally accepted accounting
principles, including, without limitation, all such items as goodwill,
trademarks, trade names, brands, copyrights, patents, licenses and rights with
respect to the foregoing and unamortized debt discount and expense; and (c) the
amount, if any, at which any Capital Stock of such Person appears on the asset
side of such balance sheet.

“Original Issue Discount Security” means any senior debt security which
provides for an amount less than the principal amount thereof to be due and
payable upon a declaration of acceleration of the Maturity thereof pursuant to
the Senior Indenture.

“Person” means any individual, corporation, partnership, limited liability
company, joint venture, association, joint-stock company, trust, unincorporated
organization or government or any agency or political subdivision thereof.

“Principal Domestic Property” means any (1) developed oil or gas producing
property or (2) processing or manufacturing plant, in each case which we or any
Consolidated Subsidiary own or lease as of the date of the Senior Indenture or
thereafter and which is located in the continental United States (provided,
however, that any such property or plant declared by our Board of Directors by
Board Resolution not to be of material importance to our and our Consolidated
Subsidiaries’ business, taken as a whole, will be excluded from the foregoing
definition).

“Production Payment” means any economic interest in oil, gas or mineral
reserves which (1) entitles the holder thereof to a specified share of future
production from such reserves, free of the costs and expenses of such
production, and (2) terminates when a specified quantity of such share of future
production from such reserves has been delivered or a specified sum has been
realized from the sale of such share of future production from such reserves.

“Redemption Date” when used with respect to any senior debt security to be
redeemed, means the date fixed for such redemption by or pursuant to the Senior
Indenture.

“Secured Debt” means any Indebtedness of us or any Consolidated Subsidiary
for borrowed money, secured by a Lien on any Principal Domestic Property or on
any shares of Capital Stock or on any Indebtedness of any Consolidated
Subsidiary which owns any Principal Domestic Property.

“Short-Term Borrowing” means all Indebtedness in respect of borrowed money
maturing on demand or within one year from the date of the creation thereof and
not directly or indirectly renewable or extendible, at the option of the debtor,
by its terms or by the terms of any instrument or

9

agreement relating thereto, to a date one year or more from the date of the
creation thereof; provided that Indebtedness in respect of borrowed money
arising under a revolving credit or similar agreement which obligates the lender
or lenders to extend credit over a period of one year or more will constitute
Funded Debt and not Short-Term Borrowing, even though it matures on demand or
within one year from the date as of which such Short-Term Borrowing is to be
determined.

“Subsidiary” means a Business Entity more than 50% of the outstanding Voting
Stock of which is owned, directly or indirectly, by us or by one or more of our
other Subsidiaries, or by us and one or more of our other Subsidiaries.

“Voting Stock” means, with respect to any Business Entity, any class or
series of Capital Stock of such Business Entity the holders of which are
ordinarily, in the absence of contingencies, entitled to vote for the election
of, or to appoint or to approve the appointment of, the directors, trustees or
managing members of, or other persons holding similar positions with, such
Business Entity.

Consolidation, Merger or Sale

The Senior Indenture generally permits us to consolidate with, merge into or
convey, transfer or lease our properties and assets substantially as an
entirety, to any Business Entity, so long as, immediately after giving effect to
such transaction, no event of default under the Senior Indenture or event which,
after notice or lapse of time or both, would become an event of default shall
have occurred and be continuing. However, any successor or acquiror of such
assets must assume all of our obligations under the Senior Indenture and the
senior debt securities and be organized and existing under the laws of the
United States of America, any state thereof or the District of Columbia.

Events of Default Under the Senior Indenture

The following are events of default under the Senior Indenture with respect
to each series of senior debt securities:

failure to pay any installment of interest upon any senior debt security of
such series when it becomes due and payable, and continuance of such failure to
pay for a period of 30 days; or

failure to pay the principal of any senior debt security of such series when
due;

failure to perform or breach of any other covenant or warranty contained in
the senior debt securities or the Senior Indenture (other than a covenant or
warranty specifically benefiting only another series of senior debt securities),
and the continuance of such failure for a period of 90 days after we receive
notice from the Senior Indenture Trustee or holders of at least 25% in principal
amount of the outstanding senior debt securities of that series;

certain events of bankruptcy, insolvency or reorganization relating to us;
and

any other event of default specified in the prospectus supplement or pricing
supplement, if any, relating to that series of senior debt securities.

If an event of default with respect to senior debt securities of any series
occurs and is continuing, the Senior Indenture Trustee or the holders of at
least 25% in principal amount of the outstanding senior debt securities of that
series, by notice in writing to us (and to the Senior Indenture Trustee if
notice is given by such holders), may declare the principal of (or if such
senior debt securities are Original Issue Discount Securities, the portion of
the principal amount specified in the applicable prospectus supplement or
pricing supplement, if any), and accrued interest, if any, on the senior debt
securities of such series to be due and payable immediately. At any time after
such a declaration of acceleration has been made and before a judgment or decree
for payment of the money due has been obtained holders of a majority in
principal amount of the outstanding senior debt securities of that

10

series, by written notice to us and the Senior Indenture Trustee, may rescind
and annul such declaration and its consequences if:

we have paid or deposited with the Senior Indenture Trustee a sum sufficient
to pay all overdue installments of interest on the senior debt securities of
that series, the principal of any senior debt securities of that series which
have become due otherwise than by such declaration of acceleration and interest
thereon, to the extent payment of such interest is lawful, interest on overdue
installments of interest, all sums paid or advanced by the Senior Indenture
Trustee, the reasonable compensation, expenses, disbursements and advances of
the Senior Indenture Trustee, its agents and counsel and any other amount due to
the Senior Indenture Trustee under the Senior Indenture, and

all events of default with respect to outstanding senior debt securities of
that series, other than the non-payment of the principal of and interest on such
senior debt securities which became due solely by such declaration of
acceleration, have been cured or waived in accordance with the terms of the
Senior Indenture.

The holders of a majority in principal amount of the outstanding senior debt
securities of any series may waive any past default with respect to that series
and its consequences, except defaults regarding:

payment of principal or interest; or

covenants that cannot be modified or amended without the consent of the
holder of each outstanding senior debt security of such series affected (as
described under “:Modification of Senior Indenture; Waiver” below).

Any waiver shall cure such default and the corresponding event of default.

Subject to the terms of the Senior Indenture, the Senior Indenture Trustee
will be under no obligation to exercise any of its rights or powers under the
Senior Indenture at the request or direction of any of the holders of the
applicable series of senior debt securities, unless the holders have offered the
Senior Indenture Trustee reasonable security or indemnity against costs,
expenses and liabilities to be incurred in compliance with such request. The
holders of a majority in principal amount of the outstanding senior debt
securities of any series will have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the Senior
Indenture Trustee, or exercising any trust or power conferred on the Senior
Indenture Trustee, with respect to the senior debt securities of that series,
provided that:

the direction given to the Senior Indenture Trustee is not in conflict with
any law or the Senior Indenture;

the Senior Indenture Trustee may take any other action deemed proper by it
which is not inconsistent with that direction; and

the Senior Indenture Trustee has not determined that the action would be
unjustly prejudicial to the holders not involved in the proceeding.

A holder of the senior debt securities of any series will have the right to
institute a proceeding under the Senior Indenture or to appoint a receiver or
trustee, or to seek other remedies only if:

the holder has given written notice to the Senior Indenture Trustee of a
continuing event of default with respect to that series;

the holders of at least 25% in principal amount of the outstanding senior
debt securities of that series have made written request, and have offered
reasonable indemnity, to, the Senior Indenture Trustee to institute the
proceedings as trustee; and

11

the Senior Indenture Trustee does not institute the proceeding, and does not
receive from the holders of a majority in principal amount of the outstanding
senior debt securities of that series other conflicting directions, within 60
days after the notice, request and offer of indemnity.

The Senior Indenture provides that no holder or group of holders of senior
debt securities will have any right to affect, disturb or prejudice the rights
of other holders, obtain or seek priority or preference over another holder or
enforce its rights under the Senior Indenture except as provided in the Senior
Indenture for the equal and ratable benefit of all holders.

These limitations on instituting proceedings do not apply to a suit
instituted by a holder of senior debt securities to enforce the payment of the
principal of or interest on the senior debt securities.

We will periodically file statements with the Senior Indenture Trustee
regarding our compliance with the conditions and covenants in the Senior
Indenture.

Modification of Senior Indenture; Waiver

We and the Senior Indenture Trustee may amend or supplement the Senior
Indenture without the consent of any holders to, among other things:

evidence the succession of another Business Entity to us and the assumption
by such successor of our covenants in the Senior Indenture and the senior debt
securities;

add to our covenants, agreements and obligations for the benefit of the
holders of all senior debt securities or any series thereof, or to surrender any
right or power the Senior Indenture confers upon us;

add to or change any of the provisions of the Senior Indenture to provide
that bearer securities may be registrable as to principal, to change or
eliminate any restrictions (including restrictions relating to payment in the
United States) on the payment of principal of or any premium or interest, if
any, on bearer securities, to permit bearer securities to be issued in exchange
for registered securities, to permit bearer securities to be issued in exchange
for bearer securities of other authorized denominations or to permit the
issuance of senior debt securities in uncertificated form;

establish the form and terms of the senior debt securities of any series and
(unless prohibited by the terms of the senior debt securities of any series
pursuant to the Senior Indenture) to provide for the re-opening of a series of
senior debt securities and for the issuance of additional senior debt securities
of such series;

evidence and provide for the acceptance of appointment under the Senior
Indenture of a successor Senior Indenture Trustee with respect to the senior
debt securities of one or more series;

cure any ambiguity, to correct or supplement any provision in the Senior
Indenture which may be inconsistent with any other provision in the Senior
Indenture or make other provisions with respect to matters or questions arising
under the Senior Indenture;

add, change or eliminate any provisions of the Senior Indenture (which
addition, change or elimination may apply to one or more series of senior debt
securities), provided that the addition, change or elimination neither (a)
applies to any senior debt security of any series created prior to the execution
of the supplemental indenture that is entitled to the benefit of the provision
nor (b) modifies the rights of holders of those senior debt securities with
respect to those modified provisions;

add to or change or eliminate any provision of the Senior Indenture as shall
be necessary to comply with any amendments to the Trust Indenture Act or to
otherwise maintain qualification

12

of the Senior Indenture under the Trust Indenture Act or to comply with the
rules of any applicable depositary;

secure the senior debt securities; or

change anything else that does not adversely affect the interests of any
holder of senior debt securities.

In addition, under the Senior Indenture, the rights of holders of a series of
senior debt securities may be changed by us and the Senior Indenture Trustee
with the written consent of the holders of at least a majority in principal
amount of the outstanding senior debt securities of each series that is
affected. However, no change may be made without the consent of the holder of
each outstanding senior debt security affected if such change would, among other
things:

change the stated maturity of principal of, or any installment of principal
or interest on, any such senior debt security;

reduce the principal amount of, or the rate of interest on, or any premium
payable on, any such senior debt security;

reduce the principal of any such Original Issue Discount Security that would
be due and payable upon declaration of acceleration;

change the place where, or currency in which, any principal of or interest on
any such senior debt security is payable;

impair the right to institute suit for the enforcement of any payment of any
such senior debt security on or after the stated maturity thereof (or, in the
case of redemption, on or after the Redemption Date or, in the case of any
senior debt security which is subject to repurchase or redemption by us at the
option of the holders, on or after the date fixed for such repurchase or
redemption);

reduce the percentage in principal amount of outstanding senior debt
securities of any series, the holders of which are required to consent to any
such change, or the consent of whose holders is required for any waiver (of
compliance with certain provisions of the Senior Indenture or certain defaults
thereunder and their consequences) with respect to the senior debt securities of
such series provided for in the Senior Indenture; and

modify any of the foregoing requirements or the provisions regarding waivers
of any covenant or past default other than to increase the percentage of holders
required for consent or waiver or add consent requirements for modification or
waiver of other provisions.

Form, Exchange and Transfer

The senior debt securities of each series may be issued as registered
securities, as bearer securities (with or without coupons) or both. Unless
otherwise specified in the applicable prospectus supplement or the pricing
supplement, if any, registered securities will be issued in denominations of
$1,000 and any integral multiple thereof and bearer securities will be issued in
denominations of $5,000 and $100,000. Subject to the terms of the Senior
Indenture and the limitations applicable to global securities described in the
applicable prospectus supplement or the pricing supplement, if any, registered
securities will be exchangeable for other registered securities of the same
series, in any authorized denomination and of like tenor and aggregate principal
amount.

Subject to the terms of the Senior Indenture and the limitations applicable
to global senior debt securities set forth in the applicable prospectus
supplement or pricing supplement, if any, senior debt securities issued as
registered securities may be presented for exchange or for registration of
transfer (duly endorsed or with the form of transfer duly executed) at the
office of the registrar or at the office

13

of any transfer agent we designate for that purpose. Unless otherwise
provided in the senior debt securities to be transferred or exchanged, no
service charge will be made for any registration of transfer or exchange, but we
may require payment of any taxes or other governmental charges. We have
appointed the Senior Indenture Trustee as registrar. Any transfer agent (in
addition to the registrar) initially designated by us for any senior debt
securities will be named in the applicable prospectus supplement or pricing
supplement. We may at any time designate additional transfer agents or rescind
the designation of any transfer agent or approve a change in the office through
which any transfer agent acts, except that we will be required to maintain a
transfer agent in each place of payment for the senior debt securities of each
series.

If the senior debt securities of any series are to be redeemed, we will not
be required to:

issue, register the transfer of, or exchange any senior debt securities of,
that series during a period beginning at the opening of business 15 days before
any selection of senior debt securities for redemption and ending, in the case
of registered securities, on the day of mailing of the relevant notice of
redemption and, in the case of bearer securities, the first publication date of
the notice, or if the senior debt securities of that series are also issuable as
registered securities and there is no publication, on the day of mailing of the
notice;

in the case of registered securities, register the transfer of or exchange
any senior debt securities so selected for redemption, in whole or in part,
except the unredeemed portion of any registered security being redeemed in part;
or

in the case of bearer securities, exchange any senior debt securities so
selected for redemption, except to exchange a bearer security for a registered
security that is immediately surrendered for redemption.

Global Senior Debt Securities

The senior debt securities of each series may be issued in whole or in part
in global form. A senior debt security in global form will be deposited with, or
on behalf of, a depositary, which will be named in an applicable prospectus
supplement or pricing supplement, if any. A global senior debt security may be
issued in either registered or bearer form and in either temporary or definitive
form. A global senior debt security may not be transferred, except as a whole,
among the depositary for that senior debt security and its nominees and their
respective successors. If any senior debt securities of a series are issuable as
global senior debt securities, the applicable prospectus supplement or pricing
supplement, if any, will describe any circumstances when beneficial owners of
interests in that global senior debt security may exchange their interests for
definitive senior debt securities of like series and tenor and principal amount
in any authorized form and denomination.

Discharge

Unless otherwise indicated in an applicable prospectus supplement or pricing
supplement, if any, we may terminate at any time our obligations under the
Senior Indenture with respect to any series of senior debt securities (other
than certain limited obligations, such as the obligation to transfer and
exchange senior debt securities of that series) by (1)(a) delivering all of the
outstanding senior debt securities of that series to the Senior Indenture
Trustee to be cancelled or (b) depositing with the Senior Indenture Trustee in
trust funds or non-callable United States government or government-guaranteed
obligations sufficient without reinvestment to pay all remaining principal and
interest on the series of senior debt securities and (2) complying with certain
other provisions of the Senior Indenture.

If we elect to discharge our obligations by depositing cash or United States
government or government guaranteed obligations as described above, under
present law such discharge is likely to be treated for United States federal
income tax purposes as a redemption of the senior debt securities of

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that series prior to maturity in exchange for the property deposited in
trust. In that event, each holder would generally recognize, at the time of
discharge, gain or loss for United States federal income tax purposes measured
by the difference between (1) the sum of (a) the amount of any cash and (b) the
fair market value of any property deposited in trust deemed received by such
holder (unless attributable to accrued interest) and (2) such holder’s tax basis
in the senior debt securities deemed surrendered. After the discharge, each such
holder would likely be treated as if it held an undivided interest in the cash
(or investments made therewith) and the property held in trust (or investments
made with interest received therefrom). Each such holder would generally be
subject to tax liability in respect of interest income and original issue
discount, if applicable, thereon and would recognize any gain or loss upon any
disposition, including redemption, of the assets held in trust. Although tax
might be owed, the holder of a discharged senior debt security would not receive
cash (except for current payments of interest on that senior debt security)
until the maturity or earlier redemption (or, if applicable, repurchase by us at
the option of the holder) of that senior debt security. United States federal
income tax treatment of this nature could affect the purchase price that a
holder would receive upon the sale of the senior debt securities. You are urged
to consult with your tax advisor regarding the tax consequences of the discharge
of our obligations.

Information Concerning the Senior Indenture Trustee

The Senior Indenture Trustee, other than during the occurrence and
continuance of an event of default under the Senior Indenture, undertakes to
perform only those duties as are specifically set forth in the Senior Indenture
and, upon an event of default under the Senior Indenture, must use the same
degree of care as a prudent person would exercise or use in the conduct of his
or her own affairs. Subject to this provision, the Senior Indenture Trustee is
under no obligation to exercise any of the rights or powers given it by the
Senior Indenture at the request or direction of any holder of senior debt
securities unless the Senior Indenture Trustee is offered reasonable security or
indemnity by that holder against the costs, expenses and liabilities that it
might incur. The Senior Indenture Trustee is not required to spend or risk its
own money or otherwise become financially liable while performing its duties
unless it reasonably believes that it will be repaid or receive adequate
indemnity.

The Bank of New York Mellon is a participating lender under our revolving
credit agreement and provides commercial banking services to us and our
affiliates. The Bank of New York Mellon Trust Company, N.A. is the Senior
Indenture Trustee. However, if The Bank of New York Mellon Trust Company, N.A.
acquires any conflicting interest when an event of default is pending, it must
(with certain exceptions) eliminate the conflict or resign.

Payment and Payment Agents

The person in whose name a senior debt security is registered will be treated
as the owner of such security for the purpose of receiving payment of principal
and, unless otherwise indicated in an applicable prospectus supplement or
pricing supplement, if any, interest on such senior debt security and for all
other purposes.

Unless otherwise indicated in the applicable prospectus supplement or pricing
supplement, if any, payment of interest on any senior debt securities (other
than bearer securities) on any interest payment date will be made to the person
in whose name those senior debt securities (or one or more predecessor
securities) are registered at the close of business on the regular record date
for the interest. Unless otherwise indicated in the applicable prospectus
supplement or pricing supplement, if any, principal and interest on the senior
debt securities of a particular series will be payable at the office of the
paying agents that we designate, except that payments of interest (other than
interest on bearer securities) may, at our option, be made by wire transfer or
check mailed to the address of the person entitled thereto. Unless otherwise
indicated in an applicable prospectus supplement or pricing

15

supplement, if any, any payment of an installment of interest on any bearer
security will be made only if the coupon relating to the interest installment is
surrendered.

We will be required to maintain a paying agent in each place of payment for
the senior debt securities of a particular series. Unless otherwise indicated in
the applicable prospectus supplement or pricing supplement, if any, the
corporate trust office of the Senior Indenture Trustee in The City of New York
will be designated as the paying agent for payments with respect to senior debt
securities (other than bearer securities).

All moneys that we pay to a paying agent or the Senior Indenture Trustee for
the payment of the principal or interest, if any, on any senior debt securities
which remain unclaimed at the end of two years after that principal or interest
has become due and payable will be repaid to us, and the holder of the security
thereafter may look only to us for payment thereof.

Unless otherwise indicated in an applicable prospectus supplement or pricing
supplement, if any, interest shall be computed, for fixed rate securities, on
the basis of a 360-day year comprised of twelve 30-day months, and, for variable
rate securities, on the basis of the actual number of days in the interest
period divided by 360.

Governing Law

The Senior Indenture and senior debt securities will be governed by and
construed in accordance with the law of the State of New York (without regard to
conflicts of laws principles thereof).

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PLAN OF DISTRIBUTION

We may sell the senior debt securities being offered hereby in one or more of
the following ways from time to time:

to underwriters or dealers for resale to the public or to institutional
investors;

directly to institutional investors;

directly to agents;

directly to a limited number of purchasers or to a single purchaser;

through agents to the public or to institutional investors;

if indicated in the prospectus supplement, pursuant to delayed delivery
contracts or by remarketing firms; or

through a combination of any of the previous methods of sale.

The prospectus supplements and pricing supplements, if any, will set forth
the terms of the offering of each series of senior debt securities, including
the name or names of any underwriter, dealers or agents, the purchase price of
the senior debt securities and the proceeds to us from such sale, any
underwriting discounts or agency fees and other items constituting underwriters’
or agents’ compensation, any initial public offering price, any discounts or
concessions allowed or reallowed or paid to dealers and any securities exchanges
on which the senior debt securities may be listed.

If underwriters or dealers are used in the sale, the senior debt securities
will be acquired by the underwriters or dealers for their own account and may be
resold from time to time in one or more transactions, including privately
negotiated transactions, at a fixed public offering price or prices, which may
be changed, in “at the market offerings,” at prices related to prevailing market
prices or at negotiated prices or varying prices determined at the time of sale.

Unless otherwise set forth in a prospectus supplement or a pricing
supplement, if any, the obligations of the underwriters to purchase any series
of senior debt securities will be subject to certain conditions precedent and
the underwriters will be obligated to purchase all of the series of senior debt
securities, if any are purchased.

If a dealer is utilized in the sale of senior debt securities, we will sell
the senior debt securities to the dealer, as principal. The dealer may then
resell the senior debt securities to the public at varying prices to be
determined by the dealer at the time of resale. The names of the dealers and the
terms of the transaction will be set forth in the prospectus supplement relating
to that transaction.

Senior debt securities may also be offered and sold, if so indicated in the
prospectus supplement or a pricing supplement, if any, in connection with a
remarketing upon their purchase, in accordance with a redemption or repayment
pursuant to their terms, or otherwise, by one or more firms (“remarketing
firms”) acting as principals for their own accounts or as agents for us. Any
remarketing firm will be identified and the terms of its agreement, if any, with
us and its compensation will be described in the prospectus supplement or a
pricing supplement, if any.

Underwriters, agents, dealers and remarketing firms may be entitled under
agreements entered into with us to indemnification by us against certain civil
liabilities, including liabilities under the Securities Act, or to contribution
with respect to payments which the underwriters or agents may be required to
make in respect thereof, and to reimbursement by us for certain expenses.
Underwriters, agents, dealers and remarketing firms may be customers of, engage
in transactions with, or perform services for us and our affiliates in the
ordinary course of business.

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Each series of senior debt securities will be a new issue of senior debt
securities and will have no established trading market. Unless otherwise
specified in the applicable prospectus supplement or pricing supplement, the
senior debt securities will not be listed on a national securities exchange. Any
underwriters to whom we sell senior debt securities for public offering and sale
may make a market in those senior debt securities, but such underwriters will
not be obligated to do so and may discontinue any market making at any time
without notice.

LEGAL MATTERS

Unless otherwise specified in a prospectus supplement accompanying this
prospectus a senior attorney in our legal department will provide opinions
regarding the authorization and validity of the senior debt securities. Any
underwriters will be advised about legal matters by their own counsel, which
will be named in the prospectus supplement.

EXPERTS

The consolidated financial statements and financial statement schedule of
Occidental Petroleum Corporation and its subsidiaries as of December 31, 2010
and 2009, and for each of the years in the three-year period ended December 31,
2010, and management’s assessment of the effectiveness of internal control over
financial reporting as of December 31, 2010 have been incorporated by reference
herein and in the registration statement in reliance upon the reports of KPMG
LLP, independent registered public accounting firm, incorporated by reference
herein, and upon the authority of said firm as experts in accounting and
auditing.

Ryder Scott Company, L.P., independent petroleum engineering consultants,
reviewed Occidental’s oil and gas estimation process, which review information
is included in Occidental’s Annual Report on Form 10-K for the year ended
December 31, 2010, which is incorporated by reference in this prospectus. Ryder
Scott’s review information is incorporated by reference herein in reliance upon
the authority of said firm in such matters.

18

Occidental Petroleum Corporation

$ % Senior Notes due 20

$ % Senior Notes due 20

PRELIMINARY PROSPECTUS SUPPLEMENT

Joint Book-Running Managers

August , 2011