OBJECTIVE： To investigate the improvement effects of Yinhuang mixture extract （YHA） on biliation and liver function of intrahepatic cholestasis model rats. METHODS： SD rats were randomly divided into blank group， model group， positive group （ursodesoxycholic acid， 45 mg/kg） and YHA high-dose， medium-dose and low-dose groups [37.8， 18.9， 9.45 g（crude drug）/kg]， with 10 rats in each group. Treatment groups were given relevant medicine intragastrically， and blank group and model group were given constant volume of normal saline intragastrically， once a day， for consecutive 5 d. 3 d after administration， except for blank group， those groups were given α-naphthyl isothiocyanates intragastrically to induce intrahepatic cholestasis model. 1 h after last administration， 2 h volume of bile， serum levels of TBIL， TBA， ALT， AST and ALP were detected； pathological changes of liver were observed. RESULTS： Compared with blank group， the 2 h volume of bile decreased significantly in model group， and serum levels of TBIL， TBA， ALT， AST and ALP increased significantly （P＜0.01）. The pathological injury was found in liver tissue. Compared with model group， except for serum level of ALP in positive group， YHA low-dose and medium-dose groups and serum level of TBIL in YHA low-dose group， another indexes of other treatment groups were improved significantly （P＜0.05 or P＜0.01）. Except for YHA low-dose group， pathological injure of other treatment groups were improved significantly. CONCLUSIONS： YHA can improve the biliation and liver function of rats with intrahepatic cholestasis induced by α-naphthyl isothiocyanates.