Exhibit 4 - --------- PACIFIC STATE BANCORP March 20, 2003 Securities and Exchange Commission Washington, DC 20549 Re: Pacific State Bancorp Commission File No. 000-49892 To whom it may concern: Pursuant to the requirements set forth in paragraph (b)(4)(iii) of item 601 of Regulation S-K, and in connection with the filing of its Annual Report on Form 10-K for the year ended December 31, 2002, Pacific State Bancorp hereby agrees to file with the Commission, upon request, a copy of the Company's Indenture dated June 26, 2002, for its $5 Million in principal amount of Floating Rate Junior Subordinated Deferrable Interest Debentures due 2032, issued to Pacific State Statutory Trust I. PACIFIC STATE BANCORP By: /s/ STEVEN A. ROSSO ------------------------------ Steven A. Rosso, President/CEO 19