Objective: To investigate protective effect of Jiawei Shengmaisan against acute myocardial ischemia/reperfusion injury in rats. Methods: The acute myocardial ischemia/reperfusion injury in rats was induced by ligating the anterior descending coronary artery in SD rats and administered different dosage jiawei shengmaisan decotion into duodenum, myocardial infarction degree(MID) was calculated by detcting myocardial infarction area with nitroblue tetrazolium(NBT) assay,SOD activities and MDA、NO contents were detected with biochemical assay. Results: Jiawei shengmaisan can significantly decreased MID and MDA contents in serum,increased SOD activities and NO contents in serum. Conclusions: The results showed that Jiawei shengmaisan has protective effect against acute myocardial ischemia/reperfusion injury in rats,which may be relate to its antioxygen action and NO.