Objective: To explore the value of application of choledochofiberscopy in the diagnosis and treatment of the extrahepatic bile duct disease, and the effect on reducing the incidence of the postoperative residual stone in biliary ducts. Methods:According to the case history and ultrasonography,if the common bile duct(CBD) diseases suspected,the CBD was explored by intraoperative choledochofiberscope(IOCF). During the procedure,a biliary passage mirror inducer apparatus and biliary tract probe which were manufactured by ourselves were used. Results :During LC,IOCF was performed on 385 cases of the 10 396 LC cases,and possitive findings were dicovered in 102 cases(26.49%). Among those positive patients, 67 cases belonged to stricture of the lower biliary tract; 5 cases were Mirizzi syndrome; 2 cases were carcinoma of the periampulla; 1 case was primarily carcinoma of the bile duct; 1case was ascarisis of the biliary system. Conclusions:IOCF is a good inspect technique with high success rate and clear image of bile duct, it can discover the common duct diseases which are difficult to be diagnosed through the routine examination.At the same time, it can provide the locative and qualitive diagnosis, determine reasonable methods of operation,and effectively provent postoperative complications.