Objective: To observe the impacts of Xinnaoning capsules on the aortic intimal structure, serum levels of diponectin (APN) and calcium sensing receptor (CaSR) expression in rats with myocardial infarction, and explore the endothelial protection mechanisms of Xinnaoning. Methods: 15 male Sprague Dawley (SD) rats in sham operation group were randomly selected from 60 rats, the rest 45 rats were fed with high fat diet for 6 weeks and received coronary artery ligation operation. The successful modeling rats were randomly divided into model group, western medicine group and traditional Chinese medicine(TCM) group, and fed with high fat diet for 8 weeks. The sham operation group fed with normal diet. The western medicine group and TCM group received atorvastatin and Xinnaoning capsules, respectively; the sham operation group and model group received same amount of distilled water. After treatment of 4 weeks, the aortic intimal structure was observed by hematoxylin-eosin (HE); the serum levels of triacylglycerol (TG), total cholesterol (TC), low density lipoprotein (LDL) and high density lipoprotein (HDL) were measured by microplate test; serum levels of APN and CaSR expression were determined by enzyme linked immunosorbent assay (ELISA) and Western blot, respectively. Results: Compared with sham operation group, aortic intimal structure derangement and plaque formation in intima in model group, and serum levels of TG, TC, LDL and CaSR expression were increased; HDL and APN were decreased (P<0.05). Compared with model group, the endarterium was more smooth in the western medicine group and TCM group, serum levels of TG, TC, LDL and CaSR expression were decreased; HDL and APN were increased (P<0.05). And there were no significant differences between western medicine group and TCM group (P>0.05). Conclusions Xinnaoning capsules are effective for myocardial infarction.