Exhibit 99.1



                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


     In connection  with this amended Annual Report of  UnionBanCal  Corporation
(the  "Company") on Form 10-K/A for the period ending December 31, 2002 as filed
with the Securities and Exchange  Commission on the date hereof (the  "Report"),
I, Norimichi Kanari, Chief Executive Officer of the Company,  certify,  pursuant
to  18  U.S.C.  Section  1350,  as  adopted  pursuant  to  Section  906  of  the
Sarbanes-Oxley Act of 2002, that, to my knowledge:

     (1) The Report fully  complies  with the  requirements  of Section 13(a) or
         15(d) of the Securities Exchange Act of 1934; and

     (2)  The  information  contained  in the  Report  fairly  presents,  in all
material  respects,  the  financial  condition  and results of operations of the
Company.



Dated:  July 10, 2003
      -------------------



                             By:    /s/ NORIMICHI KANARI
                                ---------------------------------
                                        Norimichi Kanari
                                    Chief Executive Officer