CT scan is widely used int he evaluation of hepatogiliary system and contrast study is generally performed with non-biligary contrast media. Therefore the normal intrahepatic bile ducts are not readily visible adn also extrahepatic bile ducts are occasionally not discriminated from adjacent structures, in spite of improved resolution of the CT scanner. This study was performed to evaluate the usefulness of cholangiographic enhancement in biliary CT examination. In the control group(n=5), we measured the CT number of the peripheral hepatic duct, periportal duct, common bile duct and gall bladder, respectively, at the interval of 30 minutes up to 2 hours after intervenous infusion of biliscopin(30ml) and observed time-density relationship of infused biliscopin in the biliary system. In the patient group(n=23), we observed visualization rate of the biliary system and serum bilirubin level at 30 minutes after infusion of biliscopin(30ml). The results were as follows : 1. The peak ensity occured at 30 minutes after infusion of biliscopin. 2. Visualization rate was 100% in normal bilirubing group wherease it was 91.7% in abnormal bilirubin group. 3. The cholangiogrphic enhancement of biliary CT scan is useful in the evaluation of intra-and extrahepatic biliary system.