【Abstract】 Objective To explore the effects of fosinopril combined with irbesartan on hemodynamics, serum myocardial enzymology and SOD, CAT and GSH-Px activities in rats with experimental myocardial ischemia-reperfusion injury (MIRI). Methods Wister rats were randomly divided into sham operation group, model group, fosinopril group (20 mg/kg) , irbesartan group (100 mg/kg) and combined group (10 mg/kg+50 mg/kg). The MIRI models were established in model group and drug administration group. The left ventricular systolic pressure (LVSP) , the maximum increase and decrease rates of left ventricular pressure (土dp/dtmax) , arterial systolic blood pressure (SBP) , arterial diastolic blood pressure (DBP) and heart rate (HR) were recorded among the groups, and the mean arterial pressure (MAP) were calculated. The serum aspartate aminotransferase (AST) , lactate dehydrogenase (LDH) , creatine kinase isoenzyme (CK-MB) and erythrocyte membrane ATPase activities were detected. The myocardial infarct size (MIS) was calculated. The serum superoxide dismutase (SOD) , catalase (CAT) and glutathione peroxidase (GSH-Px) activities were determined. Results Compared with model group, the levels of MIS, SBP, DBP and MAP and the activities of AST, LDH and CK-MB were significantly decreased in fosinopril group, irbesartan group and combined group, and the LVSP, 土dp/ dtmax, SOD, CAT, GSH-Px and Ca2+ -ATPase activities were significantly increased (P<0.05) , but there was no significant difference in HR(P〉0.05). Conclusion Low dose fosinopril combined with irbesartan can effectively improve hemodynamics, decrease myocardial enzyme release and enhance antioxidant enzyme activity in MIRI rats. And it has comparable efficacy with simple high-concentration of fosinopril or irbesartan.