The radioactive 131I-Rose bengal serial scintiphotography was performed in 62 patients with the hepatobiliary diseases and in 20 normal subjects. This approach permitted visualization of the hepatic uptake of 131I-Rose bengal from the circulation and its excretion into the biliary trees and the intestines. In some of these patients, gallbladder function was examined, using eggs as a gallbladder constrictor. The time of maximum hepatic uptake was well correlated to the conventional biochemical liver function tests. In addition to 131I-Rose bengal scintiphotography, 198Au-colloid scintiphotography was also performed to make comparison of these two tests. The results obtained were as follows:1) In normal subjects, the maximum hepatic uptake of 131I-Rose bengal occurred at 23¡¾2.9 minutes, the initial hepatic excretion at 34¡¾5.1 minutes, the visualization of the gallbladder at 29¡¾5.7 minutes and the intestinal visualization at 54¡¾25.8 minutes. The radioactivity in the gallbladder decreased to 10.7¡¾5.0% one hour after the ingestion of eggs. 2) In the patients with cirrhosis of the liver, there was a delayed and decreased hepatic uptake. The maxium hepatic uptake occurred at 43¡¾12.9 minutes. The differences in the results of uptake between the cirrhotic and the normal group were statistically significant. The initial hepatic excretion occurred at 60¡¾18.5 minutes and had tendency of delaying compared with the normal controls. The gallbladder was visualized in 13 of 16 cases(81%) and its visualization occurred at 49¡¾14.6 minutes with a tendency to be delayed compared with the normal controls. The intestinal visualization occurred at 63¡¾15.8 minutes and its delaying tendency was somewhat more prominent. 3) In patients with hepatitis, the maximum hepatic uptake occurred at 59¡¾21.4 minutes and was significantly delayed. The initial hepatic excretion occurred at 82¡¾34.3 minutes and the results revealed a delaying tendency. The gallbladder was visualized in 15 of 20 cases (75%) at 57¡¾18.7 minutes, which was significantly delayed. The intestinal visualization was noted in all cases with marked delay. 4) In patients with obstructive jaundice, the maximum hepatic uptake was noted at 83¡¾14.7 minutes, showing the most significant delay. The hepatic excretion into biliary trees and intestines was not entirely noted in all cases except the only case with gallbladder visualization. 5) In patients with cholelithiasis, the maxium hepatic uptake and the initial hepatic excretion were slightly delayed with mean times of 39¡¾11.2 and 48¡¾17.1 minutes respectively. The visualization of the gallbladder was demonstrated in 10 of 17 cases (59%) and occurred at 52¡¾25.6 minutes with a slight delay. The intestinal visualization occurred at 67¡¾47.7 minutes and was slightly delayed. 131I-Rose bengal in the gallbladder remained high, 49.3¡¾21.3%, which suggested quantitatively decreased power of gallbladder construction. 6) The time of the maximum hepetic uptake was correlated well to BSP retention and serum alkaline phosphatase ativity. However, the maximum hepatic uptake had no definite correlation with serum albumin, serum globulin, TTT, serum cholesterol, SGPT or SGOT. 7) In the diagnosis of the hepatobiliary diseases with jaundice, 131I-Rose bengal serial scintiphotography has proved to be more useful than