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 the Annual Report of Commerce Bancshares, Inc. (the “Company”) on Form 10-K for the year ended December 31, 2002 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), David W. Kemper, Chief Executive Officer of the Company, hereby certifies, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

      (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.

/s/ DAVID W. KEMPER

David W. Kemper

Chief Executive Officer

March 12, 2003