As filed with the Securities and Exchange Commission on July 15, 2005
                         Registration No:  333-________

--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

--------------------------------------------------------------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933

--------------------------------------------------------------------------------

                               UNOCAL CORPORATION
               (Exact name of registrant specified in its charter)

         Delaware                                      95-3825062
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

         2141 Rosecrans Avenue, Suite 4000, El Segundo, California 90245
          (Address, including zip code, of Principal Executive Offices)

                    UNOCAL DEFERRED COMPENSATION PLAN OF 2005
                            (Full title of the plan)

                             SAMUEL H. GILLESPIE III
         Senior Vice President, Chief Legal Officer and General Counsel
         2141 Rosecrans Avenue, Suite 4000, El Segundo, California 90245
                                 (310) 726-7600
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

--------------------------------------------------------------------------------
                         CALCULATION OF REGISTRATION FEE
---------------------- ------------- ---------- ----------------- --------------
    Title of each                     Proposed      Proposed
      class of                         maximum       maximum          Amount
     securities           Amount      offering      aggregate           of
       to be              to be         price        offering      registration
     registered         registered    per unit        price             fee
---------------------- ------------- ----------- ---------------- --------------
Deferred Compensation   $40,000,000     100%      $40,000,000 (2)      $4,708
Obligations (1)
---------------------- ------------- ----------- ---------------- --------------

(1) The Deferred Compensation Obligations being registered are general unsecured
obligations of Unocal Corporation ("Unocal") to pay deferred compensation in the
future to participating members of a select group of management or highly
compensated employees in accordance with the terms of the Unocal Deferred
Compensation Plan of 2005 (the "Plan").

(2) Estimated solely for the purpose of calculating the registration fee in
accordance with Rule 457(c).


<PAGE>
                PART II - INFORMATION NOT REQUIRED IN PROSPECTUS

Item 3.  Incorporation of Documents by Reference.

There are hereby incorporated by reference in this registration statement the
following documents heretofore filed with the Securities and Exchange Commission
(the "Commission"):

a.   Our Annual Report on Form 10-K, for the fiscal year ended December 31,
     2004;

b.   Our Quarterly Report on Form 10-Q for the quarterly period ended March 31,
     2005;

c.   Our Current Reports on Form 8-K dated and filed with the Commission on
     February 14, March 31, April 4 (as amended) and 7, May 10, 23, 24 and 26,
     June 9, 10, 24 and 30 and July 1 (excluding Item 2.02 and Exhibit 99.1),
     6, 13 and 15 2005; and

d.   All of our other reports filed pursuant to Section 13(a) or 15(d) of the
     Securities Exchange Act of 1934, as amended (the "Exchange Act"), since
     December 31, 2004.

All documents filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
Exchange Act prior to the filing of a post-effective amendment which indicates
that all securities offered have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference in this
Prospectus and to be a part hereof from the date of filing of such documents.

Item 4.  Description of Securities

The Plan complies with the American Jobs Creation Act of 2004 (the "JOBS Act").
The Plan provides a select group of management or more highly compensated
employees of Unocal and certain of its subsidiaries with the opportunity to
defer the receipt of certain cash compensation. The obligations of Unocal under
the Plan (the "Deferred Compensation Obligations") will be general unsecured
obligations of Unocal to pay deferred compensation in the future to
participating eligible employees (the "Participants") in accordance with the
terms of the Plan from the general assets of Unocal, and will rank pari passu
with other unsecured and unsubordinated indebtedness of Unocal from time to time
outstanding. The Deferred Compensation Obligations will be denominated and
payable in United States dollars.

Each Participant may elect to defer under the Plan a portion of his or her cash
compensation that may otherwise be payable in a calendar year. A Participant's
compensation deferrals are credited to the Participant's bookkeeping account
("Account") maintained under the Plan. Participants may elect to have the
amounts credited to his or her Account credited with interest at a rate
determined annually based on 10-year treasury bill rates. Subject to certain
restrictions, each Participant may alternatively elect to have the amounts in
the Account indexed against one or more investment options, solely for purposes
of determining amounts payable under the Plan. Unocal is not obligated to
actually invest any deferred amounts in those investment options. Each
Participant's Account is credited on a daily basis with a deemed rate of
interest and/or earnings or losses depending upon the investment performance of
the deemed investment option.


<PAGE>

Each choice offers its own risks and potential for return; no representation is
made regarding the future performance of such investment option and none of the
investment options are insured or guaranteed by the U.S. government or any other
entity.

With certain exceptions, Deferred Compensation Obligations will be paid after
the earlier of: (1) a fixed payment date, as elected by the Participant (if
any); or (2) the Participant's separation from service with Unocal or its
subsidiaries. Participants may generally elect that payments be made in a single
sum or installments in the year specified by the Participant or upon their
eligible retirement or disability, although payments will be made in the form of
a single sum for all other distribution events and Unocal may mandate payment in
the form of a single sum in certain circumstances. Additionally, a Participant
may elect to receive payment upon a Change of Control, as defined by the JOBS
Act.

No amount payable under the Plan shall be subject to anticipation, alienation,
sale, transfer, assignment, pledge, encumbrance, or charge, voluntary or
involuntary. Any attempt to dispose of any rights to benefits payable under the
Plan shall be void.

The Deferred Compensation Obligations are not subject to redemption, in whole or
in part, prior to the individual payment dates selected by the Participants.
Unocal reserves the right to amend or terminate the Plan at any time.

The total amount of the Deferred Compensation Obligations is not determinable
because the amount will vary depending upon the level of participation by
the Participants and the amounts of their compensation that they elect to
defer under the Plan. The duration of the Plan is indefinite (subject to
Unocal's ability to terminate the Plan). The Deferred Compensation Obligations
are not convertible into another security of Unocal. The Deferred Compensation
Obligations will not have the benefit of a negative pledge or any other
affirmative or negative covenant on the part of Unocal. Each Participant will be
responsible for acting independently with respect to, among other things, the
giving of notices, responding to any requests for consents, waivers or
amendments pertaining to the Deferred Compensation Obligations, enforcing
covenants and taking action upon any default by Unocal.

Item 5.  Interests of Named Experts and Counsel.

Certain legal matters in connection with the issuance and sale of the securities
offered hereby will be passed upon by Samuel H. Gillespie III, Senior Vice
President, Chief Legal Officer and General Counsel of Unocal.  Mr. Gillespie has
an employment agreement with Unocal, filed as Exhibit 10.1 to Current Report on
Form 8-K filed March 31, 2005, and is eligible to participate in the Plan.
As of June 30, 2005, Mr. Gillespie owned beneficially 21,284 shares of Common
Stock.  He also held options to purchase 34,545 shares of Unocal common stock.
In addition, Mr. Gillespie held 8,389 performance share units, which could be
paid out in up to 16,778 shares of Unocal common stock on December 31, 2006, and
8,171 performance share units, which could be paid out in up to 16,342 shares of
Unocal common stock on December 31, 2007, based upon the extent of Unocal's
achievement of performance goals determined within the first 90 days of the
award periods that began January 1, 2004 and January 1, 2005, respectively.
Performance shares are subject to accelerations and earlier payment in certain
circumstances in accordance with their terms.


                                      -2-
<PAGE>

Item 6.  Indemnification of Directors and Officers.

Section 145 of the Delaware General Corporation Law authorizes Unocal to
indemnify its directors and officers in certain circumstances against
liabilities, including expenses, incurred while acting in such capacities;
provided, generally, that any such indemnified director or officer acted in good
faith and in a manner he or she reasonably believed to be in the best interests
of the corporation and, in the case of a criminal proceeding, had no reasonable
cause to believe his or her conduct was unlawful. The Bylaws of Unocal provide
for the indemnification of Unocal's directors and officers to the maximum extent
permitted by the Delaware General Corporation Law.

In addition, Unocal has provided in its Restated Certificate of Incorporation
that it shall eliminate the personal liability of its directors to the fullest
extent permitted by the Delaware General Corporation Law and Unocal has entered
into indemnification agreements with each of its directors and officers
providing for additional indemnification. Unocal has policies of directors' and
officers' liability insurance which insure its directors and officers against
the costs of defense, settlement or payment of a judgment under certain
circumstances.

Item 8.  Exhibits.

The Exhibit Index lists the exhibits that are filed as part of this registration
statement.

Item 9.  Undertakings.

a.   The undersigned Registrant hereby undertakes:

     1.   To file,  during any period in which offers or sales are being made, a
          post-effective amendment to this registration statement:

          a.   To include any  prospectus  required  by Section  10(a)(3) of the
               Securities Act of 1933, as amended (the "Securities Act");

          b.   To reflect in the  prospectus  any facts or events  arising after
               the effective  date of this  registration  statement (or the most
               recent post-effective  amendment thereof) which,  individually or
               in  the  aggregate,   represent  a  fundamental   change  in  the
               information   set   forth   in   this   registration   statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of  securities  offered (if the total dollar value of  securities
               offered  would not  exceed  that  which was  registered)  and any
               deviation  from  the low or  high  end of the  estimated  maximum
               offering  range may be reflected in the form of prospectus  filed
               with the Commission pursuant to Rule 424(b) if, in the aggregate,
               the  changes  in  volume  and price  represent  no more than a 20
               percent change in the maximum aggregate  offering price set forth
               in the  calculation  of  Registration  Fee table in the effective
               registration statement;

          c.   To include  any  material  information  with  respect to the plan
               of distribution not previously disclosed in this statement or any
               material  change  to  such   information  in  this   registration
               statement;

                                      -3-
<PAGE>

               provided,  however, that the undertakings set forth in paragraphs
          (a) and (b)  above do not  apply  if the  information  required  to be
          included  in  a  post-effective   amendment  by  those  paragraphs  is
          contained  in  periodic  reports  filed  with  the  Commission  by the
          Registrant  pursuant to Section 13 or Section 15(d) of the  Securities
          Act of 1934 (the "Exchange Act") that are incorporated by reference in
          this registration statement.

     2.   That,  for  the  purpose  of  determining   any  liability  under  the
          Securities Act, each such post-effective  amendment shall be deemed to
          be a new  registration  statement  relating to the securities  offered
          therein,  and the  offering of such  securities  at that time shall be
          deemed to be the initial bona fide offering thereof.

     3.   To remove from  registration by means of a  post-effective  amendment,
          any of the  securities  being  registered  which remain  unsold at the
          termination of the offering.

b.   The  undersigned   Registrant  hereby  undertakes  that,  for  purposes  of
     determining  any  liability  under the  Securities  Act, each filing of the
     Registrant's  annual  report  pursuant to Section 13(a) or Section 15(d) of
     the Exchange  Act that is  incorporated  by  reference in the  registration
     statement shall be deemed to be a new  registration  statement  relating to
     the securities offered therein, and the offering of such securities at that
     time shall be deemed to be the initial bona fide offering thereof.

c.   Insofar as indemnification for liabilities arising under the Securities Act
     may be permitted to  directors,  officers  and  controlling  persons of the
     Registrant  pursuant  to  the  foregoing  provisions,   or  otherwise,  the
     Registrant  has been  advised  that in the opinion of the  Commission  such
     indemnification  is against  public  policy as expressed in the Act and is,
     therefore,  unenforceable.  In the event  that a claim for  indemnification
     against  such  liabilities  (other  than the payment by the  Registrant  of
     expenses incurred or paid by a director,  officer or controlling  person of
     the Registrant in the successful defense of any action, suit or proceeding)
     is asserted by such director,  officer or controlling  person in connection
     with the securities being  registered,  the Registrant will,  unless in the
     opinion  of  its  counsel  the  matter  has  been  settled  by  controlling
     precedent,  submit  to a court of  appropriate  jurisdiction  the  question
     whether such indemnification by it is against public policy as expressed in
     the Act and will be governed by the final adjudication of such issue.

                                      -4-
<PAGE>

                                   SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of El Segundo, State of California, on July 15, 2005.

                                               UNOCAL CORPORATION


                                               By /s/ John A. Briffett
                                                 ------------------------------
                                                 John A. Briffett
                                                 Vice President and Comptroller


Pursuant to the requirements of the Securities Act of 1933, this registration
statement has been signed by the following persons in the capacities and on the
date indicated:

     SIGNATURE                         TITLE                           DATE


Charles R. Williamson*      Chairman of the Board of Directors     July 15, 2005
-----------------------     and Chief Executive Officer
Charles R. Williamson       (Principal Executive Officer)


Terry G. Dallas*            Executive Vice President               July 15, 2005
-----------------------     and Chief Financial Officer
Terry G. Dallas             (Principal Accounting Officer)


/s/ John A. Briffett        Vice President and Comptroller         July 15, 2005
-----------------------     (Principal Accounting Officer)
John A. Briffett

John W. Creighton, Jr.*     Vice Chairman of the                   July 15, 2005
-----------------------     Board of Directors
John W. Creighton, Jr.

Craig Arnold*               Director                               July 15, 2005
----------------------
Craig Arnold

James W. Crownover*         Director                               July 15, 2005
-----------------------
James W. Crownover

Ferrell P. McClean*         Director                               July 15, 2005
----------------------
Ferrell P. McClean
                                      -5-
<PAGE>


Richard D. McCormick*       Director                               July 15, 2005
----------------------
Richard D. McCormick

Donald B. Rice*             Director                               July 15, 2005
-----------------------
Donald B. Rice

Kevin W. Sharer*            Director                               July 15, 2005
-----------------------
Kevin W. Sharer

Mark A. Suwyn*              Director                               July 15, 2005
-----------------------
Mark A. Suwyn

Marina v.N. Whitman*        Director                               July 15, 2005
-----------------------
Marina v.N. Whitman



* By /s/ John A. Briffett
     --------------------
      John A. Briffett
      Attorney-in-Fact

Pursuant to the requirements of the Securities Act of 1933, the members of the
Board Management Development and Compensation Committee who administer the
Unocal Deferred Compensation Plan of 2005, have duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of El Segundo, State of California, July 15, 2005.

                                       UNOCAL DEFERRED COMPENSATION PLAN OF 2005



                                       By          Richard D. McCormick*
                                          --------------------------------------
                                                   Richard D. McCormick
                                                  Chair, Board Management
                                          Development and Compensation Committee



                                     * By    /s/ John A. Briffett
                                          --------------------------------------
                                                 John A. Briffett
                                                 Attorney-in-Fact

                                      -6-

<PAGE>

                                  EXHIBIT INDEX
EXHIBIT
NUMBER                                             EXHIBIT

4.1* Unocal Deferred  Compensation  Plan of 2005  (incorporated  by reference to
     Exhibit 10.1 to Unocal's Current Report on Form 8-K filed July 15, 2005).

5.1  Opinion of Samuel H. Gillespie III, Senior Vice President, Chief Legal
     Officer and General Counsel of Unocal.

23.1 Consent of Independent Registered Public Accounting Firm.

23.2 Consent of Samuel H. Gillespie III, Senior Vice President, Chief Legal
     Officer and General Counsel of Unocal (included in Exhibit 5.1).

24.1 Power of Attorney.

------------------
* Previously filed

                                      -7-
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{"company-data": {"conformed-name": "UNOCAL CORP", "cik": "0000716039", "assigned-sic": "1311", "irs-number": "953825062", "state-of-incorporation": "DE", "fiscal-year-end": "0901"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-126645", "film-number": "05957929"}, "business-address": {"street1": "2141 ROSECRANS AVE", "street2": "STE 4000", "city": "EL SEGUNDO", "state": "CA", "zip": "90245", "phone": "3107267600"}, "mail-address": {"street1": "2141 ROSECRANS AVE", "street2": "STE 4000", "city": "EL SEGUNDO", "state": "CA", "zip": "90245"}}
As filed with the Securities and Exchange Commission on July 15, 2005
                         Registration No:  333-________

--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

--------------------------------------------------------------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933

--------------------------------------------------------------------------------

                               UNOCAL CORPORATION
               (Exact name of registrant specified in its charter)

         Delaware                                      95-3825062
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

         2141 Rosecrans Avenue, Suite 4000, El Segundo, California 90245
          (Address, including zip code, of Principal Executive Offices)

                    UNOCAL DEFERRED COMPENSATION PLAN OF 2005
                            (Full title of the plan)

                             SAMUEL H. GILLESPIE III
         Senior Vice President, Chief Legal Officer and General Counsel
         2141 Rosecrans Avenue, Suite 4000, El Segundo, California 90245
                                 (310) 726-7600
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

--------------------------------------------------------------------------------
                         CALCULATION OF REGISTRATION FEE
---------------------- ------------- ---------- ----------------- --------------
    Title of each                     Proposed      Proposed
      class of                         maximum       maximum          Amount
     securities           Amount      offering      aggregate           of
       to be              to be         price        offering      registration
     registered         registered    per unit        price             fee
---------------------- ------------- ----------- ---------------- --------------
Deferred Compensation   $40,000,000     100%      $40,000,000 (2)      $4,708
Obligations (1)
---------------------- ------------- ----------- ---------------- --------------

(1) The Deferred Compensation Obligations being registered are general unsecured
obligations of Unocal Corporation ("Unocal") to pay deferred compensation in the
future to participating members of a select group of management or highly
compensated employees in accordance with the terms of the Unocal Deferred
Compensation Plan of 2005 (the "Plan").

(2) Estimated solely for the purpose of calculating the registration fee in
accordance with Rule 457(c).
PART II - INFORMATION NOT REQUIRED IN PROSPECTUS

Item 3.  Incorporation of Documents by Reference.

There are hereby incorporated by reference in this registration statement the
following documents heretofore filed with the Securities and Exchange Commission
(the "Commission"):

a.   Our Annual Report on Form 10-K, for the fiscal year ended December 31,
     2004;

b.   Our Quarterly Report on Form 10-Q for the quarterly period ended March 31,
     2005;

c.   Our Current Reports on Form 8-K dated and filed with the Commission on
     February 14, March 31, April 4 (as amended) and 7, May 10, 23, 24 and 26,
     June 9, 10, 24 and 30 and July 1 (excluding Item 2.02 and Exhibit 99.1),
     6, 13 and 15 2005; and

d.   All of our other reports filed pursuant to Section 13(a) or 15(d) of the
     Securities Exchange Act of 1934, as amended (the "Exchange Act"), since
     December 31, 2004.

All documents filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
Exchange Act prior to the filing of a post-effective amendment which indicates
that all securities offered have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference in this
Prospectus and to be a part hereof from the date of filing of such documents.

Item 4.  Description of Securities

The Plan complies with the American Jobs Creation Act of 2004 (the "JOBS Act").
The Plan provides a select group of management or more highly compensated
employees of Unocal and certain of its subsidiaries with the opportunity to
defer the receipt of certain cash compensation. The obligations of Unocal under
the Plan (the "Deferred Compensation Obligations") will be general unsecured
obligations of Unocal to pay deferred compensation in the future to
participating eligible employees (the "Participants") in accordance with the
terms of the Plan from the general assets of Unocal, and will rank pari passu
with other unsecured and unsubordinated indebtedness of Unocal from time to time
outstanding. The Deferred Compensation Obligations will be denominated and
payable in United States dollars.

Each Participant may elect to defer under the Plan a portion of his or her cash
compensation that may otherwise be payable in a calendar year. A Participant's
compensation deferrals are credited to the Participant's bookkeeping account
("Account") maintained under the Plan. Participants may elect to have the
amounts credited to his or her Account credited with interest at a rate
determined annually based on 10-year treasury bill rates. Subject to certain
restrictions, each Participant may alternatively elect to have the amounts in
the Account indexed against one or more investment options, solely for purposes
of determining amounts payable under the Plan. Unocal is not obligated to
actually invest any deferred amounts in those investment options. Each
Participant's Account is credited on a daily basis with a deemed rate of
interest and/or earnings or losses depending upon the investment performance of
the deemed investment option.
Each choice offers its own risks and potential for return; no representation is
made regarding the future performance of such investment option and none of the
investment options are insured or guaranteed by the U.S. government or any other
entity.

With certain exceptions, Deferred Compensation Obligations will be paid after
the earlier of: (1) a fixed payment date, as elected by the Participant (if
any); or (2) the Participant's separation from service with Unocal or its
subsidiaries. Participants may generally elect that payments be made in a single
sum or installments in the year specified by the Participant or upon their
eligible retirement or disability, although payments will be made in the form of
a single sum for all other distribution events and Unocal may mandate payment in
the form of a single sum in certain circumstances. Additionally, a Participant
may elect to receive payment upon a Change of Control, as defined by the JOBS
Act.

No amount payable under the Plan shall be subject to anticipation, alienation,
sale, transfer, assignment, pledge, encumbrance, or charge, voluntary or
involuntary. Any attempt to dispose of any rights to benefits payable under the
Plan shall be void.

The Deferred Compensation Obligations are not subject to redemption, in whole or
in part, prior to the individual payment dates selected by the Participants.
Unocal reserves the right to amend or terminate the Plan at any time.

The total amount of the Deferred Compensation Obligations is not determinable
because the amount will vary depending upon the level of participation by
the Participants and the amounts of their compensation that they elect to
defer under the Plan. The duration of the Plan is indefinite (subject to
Unocal's ability to terminate the Plan). The Deferred Compensation Obligations
are not convertible into another security of Unocal. The Deferred Compensation
Obligations will not have the benefit of a negative pledge or any other
affirmative or negative covenant on the part of Unocal. Each Participant will be
responsible for acting independently with respect to, among other things, the
giving of notices, responding to any requests for consents, waivers or
amendments pertaining to the Deferred Compensation Obligations, enforcing
covenants and taking action upon any default by Unocal.

Item 5.  Interests of Named Experts and Counsel.

Certain legal matters in connection with the issuance and sale of the securities
offered hereby will be passed upon by Samuel H. Gillespie III, Senior Vice
President, Chief Legal Officer and General Counsel of Unocal.  Mr. Gillespie has
an employment agreement with Unocal, filed as Exhibit 10.1 to Current Report on
Form 8-K filed March 31, 2005, and is eligible to participate in the Plan.
As of June 30, 2005, Mr. Gillespie owned beneficially 21,284 shares of Common
Stock.  He also held options to purchase 34,545 shares of Unocal common stock.
In addition, Mr. Gillespie held 8,389 performance share units, which could be
paid out in up to 16,778 shares of Unocal common stock on December 31, 2006, and
8,171 performance share units, which could be paid out in up to 16,342 shares of
Unocal common stock on December 31, 2007, based upon the extent of Unocal's
achievement of performance goals determined within the first 90 days of the
award periods that began January 1, 2004 and January 1, 2005, respectively.
Performance shares are subject to accelerations and earlier payment in certain
circumstances in accordance with their terms.

                                      -2-
Item 6.  Indemnification of Directors and Officers.

Section 145 of the Delaware General Corporation Law authorizes Unocal to
indemnify its directors and officers in certain circumstances against
liabilities, including expenses, incurred while acting in such capacities;
provided, generally, that any such indemnified director or officer acted in good
faith and in a manner he or she reasonably believed to be in the best interests
of the corporation and, in the case of a criminal proceeding, had no reasonable
cause to believe his or her conduct was unlawful. The Bylaws of Unocal provide
for the indemnification of Unocal's directors and officers to the maximum extent
permitted by the Delaware General Corporation Law.

In addition, Unocal has provided in its Restated Certificate of Incorporation
that it shall eliminate the personal liability of its directors to the fullest
extent permitted by the Delaware General Corporation Law and Unocal has entered
into indemnification agreements with each of its directors and officers
providing for additional indemnification. Unocal has policies of directors' and
officers' liability insurance which insure its directors and officers against
the costs of defense, settlement or payment of a judgment under certain
circumstances.

Item 8.  Exhibits.

The Exhibit Index lists the exhibits that are filed as part of this registration
statement.

Item 9.  Undertakings.

a.   The undersigned Registrant hereby undertakes:

     1.   To file,  during any period in which offers or sales are being made, a
          post-effective amendment to this registration statement:

          a.   To include any  prospectus  required  by Section  10(a)(3) of the
               Securities Act of 1933, as amended (the "Securities Act");

          b.   To reflect in the  prospectus  any facts or events  arising after
               the effective  date of this  registration  statement (or the most
               recent post-effective  amendment thereof) which,  individually or
               in  the  aggregate,   represent  a  fundamental   change  in  the
               information   set   forth   in   this   registration   statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of  securities  offered (if the total dollar value of  securities
               offered  would not  exceed  that  which was  registered)  and any
               deviation  from  the low or  high  end of the  estimated  maximum
               offering  range may be reflected in the form of prospectus  filed
               with the Commission pursuant to Rule 424(b) if, in the aggregate,
               the  changes  in  volume  and price  represent  no more than a 20
               percent change in the maximum aggregate  offering price set forth
               in the  calculation  of  Registration  Fee table in the effective
               registration statement;

          c.   To include  any  material  information  with  respect to the plan
               of distribution not previously disclosed in this statement or any
               material  change  to  such   information  in  this   registration
               statement;

                                      -3-
provided,  however, that the undertakings set forth in paragraphs
          (a) and (b)  above do not  apply  if the  information  required  to be
          included  in  a  post-effective   amendment  by  those  paragraphs  is
          contained  in  periodic  reports  filed  with  the  Commission  by the
          Registrant  pursuant to Section 13 or Section 15(d) of the  Securities
          Act of 1934 (the "Exchange Act") that are incorporated by reference in
          this registration statement.

     2.   That,  for  the  purpose  of  determining   any  liability  under  the
          Securities Act, each such post-effective  amendment shall be deemed to
          be a new  registration  statement  relating to the securities  offered
          therein,  and the  offering of such  securities  at that time shall be
          deemed to be the initial bona fide offering thereof.

     3.   To remove from  registration by means of a  post-effective  amendment,
          any of the  securities  being  registered  which remain  unsold at the
          termination of the offering.

b.   The  undersigned   Registrant  hereby  undertakes  that,  for  purposes  of
     determining  any  liability  under the  Securities  Act, each filing of the
     Registrant's  annual  report  pursuant to Section 13(a) or Section 15(d) of
     the Exchange  Act that is  incorporated  by  reference in the  registration
     statement shall be deemed to be a new  registration  statement  relating to
     the securities offered therein, and the offering of such securities at that
     time shall be deemed to be the initial bona fide offering thereof.

c.   Insofar as indemnification for liabilities arising under the Securities Act
     may be permitted to  directors,  officers  and  controlling  persons of the
     Registrant  pursuant  to  the  foregoing  provisions,   or  otherwise,  the
     Registrant  has been  advised  that in the opinion of the  Commission  such
     indemnification  is against  public  policy as expressed in the Act and is,
     therefore,  unenforceable.  In the event  that a claim for  indemnification
     against  such  liabilities  (other  than the payment by the  Registrant  of
     expenses incurred or paid by a director,  officer or controlling  person of
     the Registrant in the successful defense of any action, suit or proceeding)
     is asserted by such director,  officer or controlling  person in connection
     with the securities being  registered,  the Registrant will,  unless in the
     opinion  of  its  counsel  the  matter  has  been  settled  by  controlling
     precedent,  submit  to a court of  appropriate  jurisdiction  the  question
     whether such indemnification by it is against public policy as expressed in
     the Act and will be governed by the final adjudication of such issue.

                                      -4-
SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of El Segundo, State of California, on July 15, 2005.

                                               UNOCAL CORPORATION

                                               By /s/ John A. Briffett
                                                 ------------------------------
                                                 John A. Briffett
                                                 Vice President and Comptroller

Pursuant to the requirements of the Securities Act of 1933, this registration
statement has been signed by the following persons in the capacities and on the
date indicated:

     SIGNATURE                         TITLE                           DATE

Charles R. Williamson*      Chairman of the Board of Directors     July 15, 2005
-----------------------     and Chief Executive Officer
Charles R. Williamson       (Principal Executive Officer)

Terry G. Dallas*            Executive Vice President               July 15, 2005
-----------------------     and Chief Financial Officer
Terry G. Dallas             (Principal Accounting Officer)

/s/ John A. Briffett        Vice President and Comptroller         July 15, 2005
-----------------------     (Principal Accounting Officer)
John A. Briffett

John W. Creighton, Jr.*     Vice Chairman of the                   July 15, 2005
-----------------------     Board of Directors
John W. Creighton, Jr.

Craig Arnold*               Director                               July 15, 2005
----------------------
Craig Arnold

James W. Crownover*         Director                               July 15, 2005
-----------------------
James W. Crownover

Ferrell P. McClean*         Director                               July 15, 2005
----------------------
Ferrell P. McClean
                                      -5-
Richard D. McCormick*       Director                               July 15, 2005
----------------------
Richard D. McCormick

Donald B. Rice*             Director                               July 15, 2005
-----------------------
Donald B. Rice

Kevin W. Sharer*            Director                               July 15, 2005
-----------------------
Kevin W. Sharer

Mark A. Suwyn*              Director                               July 15, 2005
-----------------------
Mark A. Suwyn

Marina v.N. Whitman*        Director                               July 15, 2005
-----------------------
Marina v.N. Whitman

* By /s/ John A. Briffett
     --------------------
      John A. Briffett
      Attorney-in-Fact

Pursuant to the requirements of the Securities Act of 1933, the members of the
Board Management Development and Compensation Committee who administer the
Unocal Deferred Compensation Plan of 2005, have duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of El Segundo, State of California, July 15, 2005.

                                       UNOCAL DEFERRED COMPENSATION PLAN OF 2005

                                       By          Richard D. McCormick*
                                          --------------------------------------
                                                   Richard D. McCormick
                                                  Chair, Board Management
                                          Development and Compensation Committee

                                     * By    /s/ John A. Briffett
                                          --------------------------------------
                                                 John A. Briffett
                                                 Attorney-in-Fact

                                      -6-
EXHIBIT INDEX
EXHIBIT
NUMBER                                             EXHIBIT

4.1* Unocal Deferred  Compensation  Plan of 2005  (incorporated  by reference to
     Exhibit 10.1 to Unocal's Current Report on Form 8-K filed July 15, 2005).

5.1  Opinion of Samuel H. Gillespie III, Senior Vice President, Chief Legal
     Officer and General Counsel of Unocal.

23.1 Consent of Independent Registered Public Accounting Firm.

23.2 Consent of Samuel H. Gillespie III, Senior Vice President, Chief Legal
     Officer and General Counsel of Unocal (included in Exhibit 5.1).

24.1 Power of Attorney.

------------------
* Previously filed

                                      -7-