Objective To explore the protective effects of Yiqi Huoxue Fang(Qi-boosting Blood-activa-ting Formula,YQHXF)on rat myocardium with myocardial infarction and its possible mechanism by ob-serving the effects of YQHXF on necrosis and apoptosis of myocardial cell necrosis.Methods Male SD rats were randomly divided into the sham-surgery group,model group,YQHXF group,and perindopril group.Animal model of myocardial infarction was built by ligating coronary artery on the left anterior de-scending branch.Subsequently,YQHXF group received intragastric administration of Yiqi Huoxue Fang (compound medicine,21 g/kg)once per day,and perindopril group was given perindopril (0.4 mg/kg)once a day;Sham-surgery group and model group received sterile distilled water without drug inter-vention.The blood in abdominal aorta was drawn,and the tissue on the peripheral area of the myocardial infarction was taken at two fixed time points (on the 7 th and 28 th day)after administration.Ultrasonic ech-ocardiography was used to detect changes on cardiac morphology and function in rats:left ventricular e-jection fraction (LVEF),left ventricular short axis ratio (LVFS),left ventricular end systolic diameter (LVIDs),left ventricular end-diastolic diameter (LVIDd);serum superoxide dismutase (SOD),gluta-thione peroxidase (gsh-px),creatine kinase (CK),lactate dehydrogenase (LDH),aspertate amin-otransferase (AST),and troponin (cTnT)were measured with ELISA method.Protein imprinting meth-od (Western Blot)was used to measure cytochrome C (CytC)and protein expression of cysteine aspartic acid and protease-3 (caspase-3)in the border zone of infarcted area.Results On the 7 th day,com-pared with the model group,LVEF and LVFS in YQHXF group and perindopril group decreased without statistical significance(P >0.05).On the 28 th day,compared with the model group,LVEF and LVFS in YQHXF group and perindopril group increased significantly(P >0.05 ).LVIDs and LVIDd decreased markedly(P <0.05);LVIDd in perindopril group decreased sharply (P <0.05),and decrease presen-ted on LVIDs without statistical significace (P >0.05).On the 7 th and 28 th day,compared with the mod-el group,CK-MB,LDH,AST,cTnT in YQHXF group and perindopril group decreased significantly (P<0.05),and SOD,GSH-PX increased significantly.On the 7 th day,protein expression of cytC,caspase-3 decreased significantly in YQHXF group and perindopril group(P <0.05).Conclusion Administra-tion of YQHXF at early stage can effectively improve myocardial infarction on cardiac structure and func-tion in rats with myocardial infarction,improve oxidation resistance of myocardial cell,and inhibit myo-cardial apoptosis and necrosis.