Abstract: Purpose : to evaluate the changes af the serum levels of immunosuppressive acidic protein ( IAP) in patients with large bowel carcinoma (LBC) and their familial members ( FM) . Methods : the serum changes of IAP in the 20 cases with LBC and 20 FM were determined using single immunodiffusion method. Results : the serum levels of IAP in patients with LBC , compared with normal subjects (NS) , were significantly increased ( P < 0. 01) . there also were statistical differences in serum levels between FM and the NS ( P < 0. 01) . conclusion : It is suggested that IAP may probably be associated with carcinogenesis of LBC. The changes of IAP may be served as an indicator of diagnosis for susceptible individuals of LBC.

Key words: immunosuppressive acidic protein, large bowel carcinoma, familial members