Objective To develop a better method for preparation of porcine model of acute myocardial infarction by permanent occlusion of the left circumflex coronary artery and minimally invasive surgery, evaluate its validity and stability, and explore its application in experimental studies of ischemic heart diseases. Methods 25 healthy female 3-month-old Bama minipigs, body weight 25±3 kg, were used in this study. The porcine model of myocardial infarction was established by minimally invasive surgery and the left circumflex artery ligation at the site of OM1 posterior position under general anesthesia. Heart function was assessed by echocardiography at 15 min before surgery, 1 hour and 4 weeks after surgery. Pathological examination was performed at 4 weeks after the left circumflex artery occlusion. The mortality and cause of death were statistically analyzed. Results The 1-hour and 4-week postoperative cardiac function was considerably decreased, showing a decreased ejection fraction from 64.2±4.6% to 48.2±5.3% (1hour after MI) and 49.7±6.1% (4 weeks after MI) (P<0.01). Pathological examination revealed that the ventricular wall was thinner and the amount of collagens was increased in the infracted area. The ventricular fibrillation rate at 1-hour after myocardial infarction was 17.3% and the infarction area was 19.2%. Conclusions A pig model of acute myocardial infarction can be prepared by our modified left circumflex coronary artery ligation at the obtuse marginal artery (OM1) and minimally invasive surgery. This model exhibits advantages such as minimal surgical trauma, high stability of the model, and low mortality, therefore, provides an ideal and economic animal model for experimental studies on acute ischemic heart diseases.