Objective To study the protective effect and possible mechanism of Guanmaitong Tablets on myocardial ischemia-reperfusion injury（ MIRI）. Methods Sixty rats were randomized into the sham operation group

model group

positive control group and Guanmaitong Tablets high-dose

middle-dose and low-dose groups

with 10 in each. The positive control group was gavaged with 600 mg /kg · d Compound Danshen Tablets. The Guanmaitong Tablets high-dose

middle-dose and low-dose groups were gavaged with 1 200 mg /kg·d

600 mg /kg·d and 300 mg /kg·d of Guanmaitong Tablets respectively. The sham operation group and model group were gavaged with the same volume of normal saline. The intragastric administration lasted for 5 days. The rat models of MIRI were established in all groups except the sham operation group. The area of MIRI was compared among groups. The activities of aspartate aminotransferase（ AST）

creatine kinase（ CK）

CK-MB and cardiac troponin T（ c-TnT） were detected. The pathological changes and number of apoptotic cells in myocardial cells were observed after MIRI. Results Comparing with the model group

the area of MIRI and number of apoptotic cells were significantly decreased in the Guanmaitong Tablets high-dose

middle-dose and low-dose groups and positive control group（ P < 0. 05 or P < 0. 01）. Comparing with the model group

the activities of AST

CK

CK-MB and c-TnT were significantly increased in all administration groups except CK-MB in the Guanmaitong Tablets low-dose group（ P < 0. 05 or P < 0. 01）. Conclusion Guanmaitong Tablets can obviously relieve MIRI

which may be relevant to improving cardiac enzymes and reducing myocardial apoptosis.