Abstract: Objective: To study the expression of Fas and Fas-L proteins in rat liver fibrosis model and the role of IFN-γ.Methods: Liver fibrosis was successfully induced in rats by subcutaneous injection of carbon tetrachloride(CCl₄).The rats were divided into fibrosis model group and IFN-γ treatment group(20 mu·kg^-1·d^-1,intramuscular injection for 12 weeks)and the group of rats without treatment was used as normal control.Fas and Fas-L proteins of the three groups were detected by immunohistochemistry.Results: Fas and Fas-L proteins were scarcely detected in the plasma of hepatocytes in the normal control,but they cound be found in the fibrous septae and hepatic sinusoid in fibrosis model rats(P<0.01).Compared with that in fibrosis models,the expression of Fas and Fas-L protein was significantly lower in rats treated with IFN-γ(P<0.05-P<0.01).Conclusions: The expression of Fas and Fas-L proteins is increased in rat liver fibrosis model.IFN-γ can inhibit the expression of Fas and Fas-L.