Abstract: AIM: To study the protective effect of a new compound,Acetyl Danshen Acid Isosorbide Mononitrate (AcDI-302), on myocardial ischemia/reperfusion(MI/R) injury and to compare its effect with that of Isosorbide Mononitrate (ISMN). METHODS: Male Spragne-Dawley rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion. The rats were randomly assigned to SHAM group, treatment group of MI/R + solvent and MI/R + ISMN and treatment group of MI/R + AcDI-302. MI/R models were prepared by temporary occlusion of the left anterior descending coronary artery. Heart rate (HR), left ventricle maximum systolic pressures (LVSP) and the maximal first derivative of developed pressure(±dp/dtmax) were monitored throughout the experiments. Myocardial infarction (MI) size and serum ereatine kinase(CK), lactate dehydrogenase(LDH), nitric oxide(NO) and malondialdehyde(MDA) of the rats were deter-mined at the end of reperfusion. RESULTS: Compared with ISMN, the new compound of AcDI-302 improved the cardiac func-tion by increasing LVSP and ±dp/dtmax, and decreased the size of myocardial infarction, the activities of CK and LDH and the level of MDA. CONCLUSION: Compared with the protective effect of ISMN, the new compound of AcDI-302 has stronger protective effects on MI/R injury in rats.