The authors studied 3 cases of Clonorchis sinensis by CT and the operative findings were compared with the preoperative findings of CT scan. Of 3 cases, 2 cases showed moderate degree dilation of gall bladder with thickening of its well and moderate or minimal degree dilation of common bile duct and intrahepatic biliary treesin CT scan. The remaining 1 case showed moderate degree dilatation of gall bladder with markedly dilated intrahepatic biliary trees. We found that the opearative findings were well corelated with the preoperative findings of CT scan. It is our belief that the CT scan in clonorchis sinensis is the most earliest and reliablemean for detremination of surgical therapy.