ObjectiveExplore the clinical effect of U- 100 double- frequency laser lithotripsy in postoperative residual intrahepatic calculus under choledochoscopy.MethodsSeverty-four patients of postoperative intrahepatic residual stones with U-100 double-frequency laser lithotripsy under choledochoscopy were analyzed retrospectively.ResultsSixty-three (85.1％) of 74 cases were treated successfully in the first operation,8cases ( 10.8％ ) obtained satisfactory outcome in the second operation,and 3 cases (4.1％) in the third.All lithotripsies were performed successfully.ConclusionsU-100 double-frequency laser lithotripsy in postoperative residual intrahepatic calculus under choledochoscopy provides a safe and effective method.