Aim To investigate the effects of ursolic acid from loquat leaves on proliferation inhibition and expression of PPAR-γ 、TGF-β1 in rat hepatic stellate cells, so as to explore the mechanism of anti-hepatic fibrosis of UA.Methods HSC-T6 cells were randomly divided into blank group, rosiglitazone control group, the low, medium and high concentration of UA group to detect the cell proliferation inhibition by CCK-8 after 24,48,72 h.The content of type collagen Ⅰ in cell culture supernatant of each group was examined by ELISA.The expression of PPAR-γ mRNA, TGF-β1 mRNA in HSC-T6 cells exposured were examined by real-time quantitative PCR.Effects on HSC-T6 PPAR-γ and TGF-β1 protein from each group were detected by immunocytochemical method.Results CCK-8 results showed that the inhibitory rate of UA on cell proliferation increased with the prolongation of drug action time(P<0.01).ELISA results showed that with the increase of the concentration of UA, the content of type Ⅰ collagen content decreased(P<0.01).Real-time PCR results showed that with the increase of the concentration of UA, and the expression of PPAR-γ mRNA increased, the expression of TGF-β1 mRNA decreased(P<0.01).The results of immunocytochemistry showed that the expression of PPAR-γ protein was increased, and the expression of TGF-β1 protein was decreased with the increase of the concentration of UA(P<0.01).All effects mentioned above were dose-dependent.Moreover, the effects in the high concentration groups were stronger than those in control group.Conclusion UA can inhibit the proliferation of HSC-T6 cells, Which may be associated with the up-regulation of PPAR-γ expression and the down-regulation of TGF-β1 expression.