The conectration of cholecystokinin infasting serum was determined by radioimmunoessay in 30 patients with gastric antrum cancer before and after radical sbutotal gastrectomy.It was 119.6±142.2pmol/L before the operation and 78.5±149.2pmol/L after the operation,which was significantly lower than that before the operation,P=0.022. The result suggests that the reduction of cholecytokinin secretion after gastrectomy was one of the important causes in the bile stasis,the disturbance of gallbladder emptying funcion and the formation of gallstone.