Objective To determine the relationship between chronic colonic schistosomiasis and colorectal carcinoma.Methods Expression levels of c-erbB-2 and DPC4 were detected by two-step and SP immunohistochemical method respectively in normal colonic mucosa of 15 cases,in colonic mucosa of 15 cases with simple schistosomiasis,20 cases of colorectal carcinoma with schistosomiasis and 20 cases of colorectal carcinoma without schistosomiasis.Results c-erbB-2 was expressed in each group with different levels,but the level in colonic mucosa with schistosomiasis was the highest compared to other groups,which had statistical significance(P