Objective To investigate various ischemia times of myocardial ischemia-reperfusion injury (MI/ RI) in Chinese miniature swine and provide the basis to establish the optimal model of MI/ RI in Chinese miniature swine. Methods Twenty-nine Chinese miniature swine were randomly divided into a sham group (n=6), 30 min ischemia group (n=7), 60 min ischemia group (n=7), and 90 min ischemia group (n=9). After pentobarbital sodium anesthesia, left coronary angiography was performed in each model group, and a balloon was exchanged into the middle of the left anterior descending branch through a wire. We elevated the ST segment on a body surface electrocardiogram and the numbers of ventricular fibrillations and defibrillations during the operation. Left ventricular ejection fraction (EF) and left ventricular fractional shortening (FS) were recorded before the operation, before reperfusion, and at 1, 2 and 3 h of reperfusion. Serum levels of creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured at the same time. The area of myocardial infarction was observed by double staining with TTC/ Evans blue. The non-reflowed area after reperfusion was observed by thioflavin S staining. Results Mortality was the highest in the 90 min ischemia group. The numbers of ventricular fibrillations and defibrillations were increased significantly with increasing ischemia time (P<0. 05, P<0. 01). Ejection fraction and fractional shortening were obviously lower after 90 min of ischemia and ay 3 h of reperfusion compared with those in the other groups (P<0. 05, P<0. 01). No significant differences were found in the electrocardiogram, areas of myocardial infarction and non-reflow, myocardial tissue staining, or serum levels of CK-MB, LDH, SOD, and MDA among model groups. Conclusions A swine model of MI/ RI with 90 min of ischemia had strong arrhythmias and high mortality, whereas models established under ischemia for 30 min with reperfusion for 3 h replicated the characteristic lesions of clinical disease with low mortality and are suitable for studies of pathogenesis and drug actions.