Abstract:Objective: Guanxin Ⅱ is a famous modern formula of traditional Chinese medicine. Guanxin Ⅱ after myocardial infarction (MI) has been shown to have beneficial effects on cardiac anatomy and function. The purpose of this study was to examine the effects of Guanxin Ⅱ on cardiac protein expression after MI. Method: Rats were randomized into 3 groups, sham, model and treating groups. Model and treating groups were fed with Guanxin Ⅱ and sham group was fed with water for 10 days before MI. MI operation is to ligate left coronary artery. 24 hours after MI, myocardial protein expression of junctional zone was assessed with 2D gel electrophoresis and mass spectra analysis. Result: Guanxin Ⅱ was found to be able to improve myocardial protein expression, especially 11 proteins. These proteins are mainly involved in suppressing changes of cell shape and structure and energy metabolism. Conclusion: Guanxin Ⅱ after MI affected myocardial protein expression. Further experiments of larger research extent should be done to receive more results.