Objective To evaluate the role of endoscopic retrograde cholangio-pancreatography(ERCP)in diagnosis of anomalous converge of the cystic duct and prevention of bile duct injuries during laparoscopic cholecystectomy(LC). Methods From July, 1992 to June, 1999, LCs were performed in 4 500 patients with gallbladder stone or cholecystitis at our center. Preoperative ERCPs were performed in 780 of all patients (14.50%). Anomalous junctions of the cystic duct with common hepatic duct were investigated and the length and caliber of these cystic duct were measured and compared with 100 control cases. Results An overall anomalous converges of the cystic duct were found in 125(16.03%) of the 780 patients undergoing ERCP. Of 780 patients undergoing LC, 35 cases were converted to open cholecystectomy(4.5%), and various complications occurred in 6 cases (0.77%), but no death and biliary duct injuries occurred. Conclusion Various types of anomalous junctions of the cystic duct could be diagnosed precisely by ERCP before LC and the preoperative examination of ERCP may be helpful in prevention of bile duct injuries and other biliary complications in the laparoscopic time.