We performed 1856 cases of ERCP from 1976 to August 1985 and among them we analyzed 116 cases of ERCP after biliary stone surgery. 1) Among 1856 cases of ERCP, biliary tract diseases were 709 cases(38.2%), and among 709 cases, 336 cases(47.4%) had stones in the biliary tract. Among 709 cases, 116 cases of ERCP after biliary tract surgery demonstrated following data. 2) Almost all cases of 116 cases(16.4%) of ERCP received cholecystectomy due to gall stone and the duration from operation to ERCP were variable. Many cases received operation in the private hospital but 31.4% cases received operation in the general hospital and university hospital. 3) Sex distribution in ERCP 116 cases of biliary tract surgery showed predominence in the female(62.1%) and most of the cases were over 40 years of age. SGOT and serum bilirubin were normal in half the cases, but alkaline phosphatase was elevated in 80 cases. Clinical impression in ERCP 116 cases of biliary tract surgery were in the order of remained CBD stone(67 cases), obstructive jaundice(24 cases), T-tube CBD stone(10 cases), pancreatitis(5 cases), cholangitis(4 cases), postop jaundice(2 cases), etc. 4) 111 cases in 116 cases of biliary tract surgery were performed ERCP and ERCP demonstrated recurrent or remained biliary tract stone in 62 cases(53.4%) and chronic pancreatis in ERCP was demonstratated in 52 cases(44.8%) So we think that biliary stone induces duronic pancreatitis. Among 62 cases of recurrent or remained CBD stone EST was performed in 35 cases and after EST good results were obtained.