Clinically, 32 cases of intrahepatic cholestasis and 30 cases of severe chronic hepatitis with a bilirubin level higher than 171 mumol/L were studied. The results showed that bilirubin was 420 mumol/L in the first group, and 480 mumol/L in the second group (P greater than 0.05); TXB2 was 306 pg/ml and 271 pg/ml (P greater than 0.05) while PGF1 alpha was 253 pg/ml and 494 pg/ml (P less than 0.05) respectively, both were higher than their normal values (P less than 0.01). The cases were divided into acute, moderate and severe types according to their pathological lesions. Experimentally, intra- and extrahepatic cholestasis and necrotic liver tissues were induced by ANIT, ligation of common bile duct, and carbon tetrachloride respectively. Bilirubin was 629 mumol/L, 124.8 mumol/L, and lower than 17.1 mumol/L (P less than 0.01); plasma TXB2 was 634 pg/ml, 1036 pg/ml, and 239 pg/ml (P less than 0.01); PGF1 alpha was 186 pg/ml, 218 pg/ml, and 868 pg/ml (P less than 0.01) in the three groups respectively. No statistic difference was found in their TXB2 and PGF1 alpha. Our studies suggested that plasma TXB2 and PGF1 alpha in the liver was not related to the severity of liver lesions. TXB2 and PGF1 alpha are positively correlated with the increase of bilirubin while TXB2 is negatively correlated with PGF1 alpha, which might serve as an index for cholestasis, and be a cause for deepening jaundice.