EXHIBIT 21 SUBSIDIARIES OF UNOCAL CORPORATION Organized under Name of Company law of - --------------- --------- Union Oil Company of California, dba California "UNOCAL" Philippine Geothermal, Incorporated California Unocal International Corporation Nevada Unocal Canada Limited Alberta Unocal Indonesia, Limited Bermuda Unocal Netherlands B.V. Netherlands Unocal Thailand, Limited Bermuda The indented companies are subsidiaries of Union Oil Company of California. The names of 147 subsidiaries are omitted inasmuch as such subsidiaries, considered in the aggregate as a single subsidiary, would not constitute a significant subsidiary.