Abstract： Objective： To study the effect of tanshinone IIA on protein expression of peroxisome proliferator- activated receptor(PPAR) signaling pathway in hyperlipidemia rats and its protective mechanism on liver. Methods： A total of 27 SD male rats of SPF grade were divided into the tanshinone group，the model group and the blank group according to the random number table method，nine rats in each group. Rats in the blank group were fed with normal diet，and rats in the tanshinone group and model group were fed with high- fat diet；all were fed for four weeks. After the model preparation，rats in the tanshinone group were intraperitoneally injected with 10 mg/(kg·d) tanshinone II A sodium sulfonate；the model group and the blank group were intraperitoneally injection with the same amount of phosphate- buffered saline； all groups lasted for eight weeks. The levels of aspartate transaminase(AST)， alanine transaminase(ALT)， low density lipoprotein- C(LDL- C)， high density lipoprotein-C(HDL-C)，triglyceride(TG) and total cholesterol(TC) were detected. The results of HE staining and oil red O staining were observed. The levels of apolipoprotein A- I(Apoa- I)， cytochromeP4504A1(CYP4A1) and protein expression of peroxisome proliferators- activated receptor α(PPARα) were detected by Western Blot. Results： Compared with those in the blank group，the levels of HDL-C，CYP4A1，Apoa-I and PPARα were decreased in the model group(P＜ 0.05， P＜0.01)， and the levels of AST， ALT， LDL- C， TG and TC were increased(P＜0.05)； 175 proteins were downregulated and 314 proteins up-regulated，with a total of 489. Compared with those in the model group，the levels of AST and ALT were decreased in the tanshinone group(P＜0.05)，and the levels of CYP4A1，Apoa-I and PPARα were increased(P＜ 0.05， P＜0.01))； there was no significant difference in the comparison of the levels of HDL- C， LDL- C， TG and TC(P＞ 0.05)；148 proteins were down-regulated and 108 proteins up-regulated，with a total of 256. Conclusion：Tanshinone IIA can promote the oxidation of fatty acids and the reverse transport of cholesterol in hyperlipidemia rats and improve PPAR signaling pathway to protect the liver.