Abstract: In the present study,we investigated the effect of persimmon tannin on the intestinal microbial by anaerobic fermentation in vitro,and the changes of microbials,the content of short-chain fatty acids and p H in fermentation broth were measured at 0, 6, 12, 24, 48 h, respectively. The results showed that incubating of persimmon tannin( 2 g / L) with the intestinal microorganisms promoted proliferation of intestinal bacteria( Lactobacillus and Bifidbacterium) siginificantly, inhibited the proliferation of harmful bacteria( Enterococci,E. coli,Clostridium bacteria and Bacteroides) notabely,and increased short chain fatty acid content and reduced the p H of the fermentation broth as compared with the control group. The results showed that persimmon tannin could regulate the microflora in intestinal tract,which might be one of the mechanisms of persimmon tannin in vivo.