Abstract: Objective To discuss the causes for failure in diagnosis and removal of gallstone using choledochoscope. Method A retrospective analysis was conducted in 714 cases of gallstone treated with choledochoscopic operations. Results Residual stones in the bile duct were found in 132 (18.5%) cases after the operation. In 54 cases the bile duct stones failed to be completely removed even before the closure. By T-tube cholangiography and choledochoscopy after the operation, 78 cases were found to have residual bile duct stones, among them 29 were complicated with intrahepatic bile duct and bile duct opening stenosis, 37 with intrahepatic bile stone and bile duct variation, and 12 with choledochus inferior segment stenosis and stone formation. Conclusion Due attention should be paid during the choledochoscopic operation to bile duct variation, bile duct opening stenosis or choledochus inferior segment stenosis, which should be carefully inspected by segments in succession to minimize the possibility of residual stones.