Serum total bile acid concentration in unicteric liver diseases was measured by enzymaticfluorometry, and the relation among surum total bile acid concentration and non-specific liver function tests, bilirubin fractions and liver biopsy specimen was evaluated. The following results were obtained. 1) Serum total bile acid concentration was elevated in the order of acute hepatitis, chronic hepatitis and liver cirrhosis. Significant elevation was observed in chronic aggresive hepatitis more than in chronic persistent hepatitis. 2) Significant correlation among serum total bile acid concentration and non-specific liver function tests were as follow, Ch-Ease and albumin in chronic hepatitis, TTT, Ch-Ease, albumin and KICG in liver cirrhosis, TTT, ZTT, CCF, γ-globulin, Ch-Ease, cholesterol, albumin and KICG in primary hepatoma, all examined tests except GOT & GPT were correlated with serum total bile acid concentration in total cases. 3) Abnormality of serum total bile acid concentration in acute hepatitis and in chronic aggresive haptitis were second to GPT, in chronic persistent hepatitis fifth in order to GPT, KICG , GOT and ZTT, and in liver cirrhosis, second following KICG. In total, the abnormality was increased in order of primary hepatoma, liver cirrhosis, chronic aggresive hepatitis, acute hepatitis and chronic persistent hepatitis. 4) Significant correlations among serum total bile acid concentration and bilirubin fractions were with esterform bilirubin and the molar ratio of glucuronic acid to ester-form bilirubin (M.R.) in chronic persistent hepatitis, with total bilirubin in chronic hepatitis and primary hepatoma. In all cases, total bilirubin, direct bilirubin and M.R. correlated with serum total bile acid concentration. 5) In chronic hepatitis and liver cirrhosis, there was good correlation among serum total bile acid concentration and histological appearance, that is, swelling and increased number of Kupffer cell, destruction of limiting plate, proliferation of collagen and elastic fiber, cell infiltration and distortion of lobular architecture.