SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549



                                    FORM 8-K



                             Current Report Pursuant
                          to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934



    Date of report (Date of earliest event reported)        December 9, 1999
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                               UNOCAL CORPORATION
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             (Exact name of registrant as specified in its charter)



                                    Delaware
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                 (State or Other Jurisdiction of Incorporation)



    1-8483                                   95-3825062
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(Commission File Number)                (I.R.S. Employer Identification No.)



2141 Rosecrans Avenue, Suite 4000, El Segundo, California         90245
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(Address of Principal Executive Offices)                       (Zip Code)



                                 (310) 726-7600
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              (Registrant's Telephone Number, Including Area Code)


Item 5.      Other Events.

Unocal Corporation  announced the appointments of Timothy H. Ling and Charles R.
Williamson to the  company's  board of directors  effective  January 1, 2000. As
announced  in August  1999,  John F.  Imle,  Jr.,  has  resigned  from the board
effective  December 31, 1999.  Mr. Imle,  who was Vice  Chairman and a director,
will  continue  to serve as a  consulting  employee of the  company.  With these
changes,  the total size of the board of directors will be 10,  including  three
company employees.

Mr. Ling was named Executive Vice President, North America Energy Operations, in
March 1999.  He joined Unocal in 1997 as chief  financial  officer and member of
the management  committee.  As CFO, Mr. Ling has a strategic  role,  focusing on
mergers,  acquisitions and investor relations. He received a bachelor of science
degree from Cornell  University in 1982 and a master of business  administration
degree from Stanford University in 1989. Prior to joining Unocal, he had been an
employee of McKinsey & Company since 1989 and a partner of the firm since 1994.

Mr.  Williamson  was  named  Executive  Vice  President,   International  Energy
Operations,  and member of the management committee in 1999. He holds a Ph.D. in
geology from the University of Texas at Austin.  Mr. Williamson joined Unocal in
1977 as a research  associate for Unocal's  Science and  Technology  Division in
Brea,  California.  In 1983, he was named chief exploration geologist for Unocal
in the United  Kingdom,  and in 1986,  he became  exploration  manager of Unocal
Netherlands.  Mr.  Williamson was named Vice President of Exploration for Unocal
Thailand in 1989. He then became Vice President,  Technology,  in 1992. In 1995,
he was appointed Vice President,  Corporate Planning and Economics.  In 1996, he
was  named  Group  Vice  President,   International  Operations.  In  1997,  Mr.
Williamson assumed the position as Group Vice President, Asia Operations.

The Bylaws of Unocal Corporation and Union Oil Company of California, as amended
to become effective January 1, 2000, are attached as exhibits under Item 7(c) of
this report.


Item 7.      Financial Statements and Exhibits.

             (c)  Exhibits

             3    Bylaws of Unocal  Corporation,  as amended to become effective
                  January 1, 2000.

             99   Bylaws of Union Oil  Company,  as amended to become  effective
                  January 1, 2000.

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Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.




                                                 UNOCAL CORPORATION
                                                 (Registrant)





Date:  December 10, 1999                         By: /s/ JOHN A. BRIFFETT
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                                                     John A. Briffett

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