To define the hepatic arterial and portal venous contribution, ^<99m>Tc-Sn colloid angiography was oerformed in various liver diseases by injecting the usual 185 MBq (5 mCi) dose. A time-activity curave of the right lobe of the liver was analized by a computer. In order to eliminate the influence due to lung, a gamma variant fit was performed on the early portion of the first peak of the liver curve and subtracted from the liver curve. The peak of the left kidney curve was chosen as markerto separate the arterial and portal venous phases. The ratio of portal venous to hepatic blood flow was decreased in the fatty liver compared with the normal liver (P<0.05). And the ratio was proportionally decreased with the progression form choronic hepatitis to liver chirosis. The method is very simple and could be applied prior to the conventional static liver imaging.