Exhibit 32.2



                            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  Quarterly  Report  of  UnionBanCal  Corporation  (the
"Company")  on Form 10-Q for the quarter  ending June 30, 2005 as filed with the
Securities and Exchange  Commission on the date hereof (the "Report"),  I, David
I.  Matson,  Chief  Financial  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:  August 5, 2005



                                    By:         /S/ DAVID I. MATSON
                                       -----------------------------------------
                                                    David I. Matson
                                                Chief Financial Officer