This paper showed the effect of acetylation of bamboo surface by anhydride acetic (AA) on tensile strength of polymer composite (PC) based on polypropylene (PP) reinforced by short bamboo fibers. The best conditions for acetylation is ratio of –OH to AA was 1:3, at the temperature of 100o C within 8 hours. The tensile strength of 50% fibers content’s PC has been increased in comparison with unreinforced PP.