Purpose : The purpose of this study is to evaluate that sequential CT scans after oral contrast ingestion canshow morphological and functional status of the biliary tree, especially for the gallbladder and assess whetherthe CT scans demonstrate other radiological informations than conventional oral cholecystography. Materials andMethods : Thirty volunteers in third decades and eight patients with hepatobiliary disease were included for thestudy. CT scans were obtained 3, 6, 9, 12 hours after oral contrast ingestion and thirty minutes after fat meal inthiry volunteers. Conventional oral cholecystography was also obtained in all volunteers at 12 hours after oralcontrast ingestion and after fat meal. We evaluate opacification of gallbladder, biliary tree, and duodenum bycontrast media on CT scans and attenuation values of gallbladder, common hepatic duct and common bile duct in eachanatomic area on CT and its sequential change. CT scans were performed 6 hours after oral contrast ingestion ineight patients with hepatobiliary disease. And gallbladder function was evaluated by opacification of gallbladderby contrast media in all patients. Results : In thirty volunteers, opacified gallbladder by contrast media wasseen in all cases in all sequential periods of time on CT scans, but in 22 cases on conventional oralcholecystography. Contrast-filled intrahepatic ducts were demonstrated in 3 cases at 3 hours after oral contrastingestion and 11 cases at 6 hours and were not seen thereafter. Contrast-filled common hepatic duct was noted in28, 18 and 4 cases respectively at 3, 6 and 9 hours after oral contrast ingestion and the CT attenuation values ofcommon hepatic ducts had become progressively decreased. Contrast-filled common bile duct was noted in 28, 18 and4 cases respectively at 3, 6 and 9 hours and the CT attenuation values of common bile ducts were not changeduntill 9 hours but slightly increased at 12 hours. Contrast media was noted in 7, 5, 6 and 5 cases at 3, 6, 9, and12 hours in cystic duct and 8, 3, 2, 5 cases in duodenum. Contrast-filled cystic duct and duodenum were noted in24 cases and 19 cases respectively on CT scans after fat meal. The CT attenuation values of gallbladder wereincreased in sequential periods of time and the difference of density of gallbladder between 3 hours and 6 hourswas statistically significant(p=0.0001). The CT attenuation values of gallbladder at 6 hours were heighter thanthat in 3 hours, statistically. Opacified gallbladder were noted in 2 cases of fatty liver(n=2), 1 case ofalcoholic liver disease(n=1), in 1 case of liver cirrhosis(n=1). Patients of gallbladder stone(n=2) orhepatocellular carcinoma(n=2) had non-opacified gallbladder on CT scans. Conclusion : The CT scans after oralcontrast ingestion can show the morphological and functional aspects of gallbladder better than conventional oralcholecystography and can also show biliary trees and other surrounding structures, so it is helpful method forassessment of not only gallbladder diseases but also other hepatobiliary diseases.