Abstract: In order to optimize the enzymolysis extraction process of ursolicacid(UA)from Ilex kudingcha C.J.Tseng and study on its protective effect of liver injury in mice.To research the effects on yield of UA,enzymolysis temperature,enzymolysis time and enzymolysis pH were optimized by response surface analysis. 0.1% CCl₄(20 mL/kg intraperitoneal injection)induced liver injury model was established in mice,then the liver protection of UA from Ilex kudingcha C.J.Tseng was evaluated by the level of AST,ALT in serum,SOD,MDA and GSH-Px in liver tissue. Histopathological examination of liver tissue also been observed. The results demonstrated that the optimum extraction condition of UA were as follows:enzymolysis temperature of 48℃,enzymolysis pH of 5.0,enzymolysis time of 1.0 h,the content of UA was(37.28±0.89) mg/g on this condition and the models provided a better fit to the real data and good predictability. The liver protection experiments showed that the UA from Ilex kudingcha C.J. Tseng could decrease the level of AST,ALT in serum,MDA in liver tissue significantly and improve the level of SOD,GSH-Px in liver tissue obviously. Liver tissue damage induced by CCl₄ was ameliorated according to the histopathological examination. In conclusion,the UA from Ilex kudingcha C.J.Tseng showed hepatoprotective effects on CCl₄-induced liver injury in mice.