<DOCUMENT>
<TYPE>EX-32.2
<SEQUENCE>8
<FILENAME>k88686exv32w2.txt
<DESCRIPTION>SECTION 1350 CHIEF FINANCIAL OFFICER CERTIFICATION
<TEXT>
<PAGE>
                                                                    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

         This certification is provided pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, 18 U.S.C. Section 1350, and accompanies the
quarterly report on Form 10-Q for the quarter ended September 30, 2004 (the
"Form 10-Q") of Mercantile Bank Corporation (the "Issuer").

         I, Charles E. Christmas, Senior Vice President, Chief Financial Officer
and Treasurer of the Issuer, certify that:

(i) the Form 10-Q fully complies with the requirements of Section 13(a) or
Section 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m(a) or
78o(d)); and

(ii) the information contained in the Form 10-Q fairly presents, in all material
respects, the financial condition and results of operations of the Issuer.

Dated: November 5, 2004

                                                 /s/ Charles E. Christmas
                                                 -------------------------------
                                                 Charles E. Christmas
                                                 Senior Vice President, Chief
                                                 Financial Officer and Treasurer


</TEXT>
</DOCUMENT>
