Objective: We aim to develop a rapid and efficient method of myocardial ischemia reperfusion (MIR) without the requirement of ventilation and chest opening in mice. Methods: Forty male Kunming mice (6-8 weeks old and weighing 18-25 g) were randomly divided into sham operation group, ischemia 15 min+reperfusion 24 h group, ischemia 30 min + reperfusion 24 h group and ischemia 45 min+reperfusion 24 h group(10 mice in each group). Mice were anesthetized with 2% isoflurane gas, the heart were fully exposed through a small incision of the forth intercostal space on the left side. After rapidly locating and ligating the left anterior descending coronary artery (LAD) for 15, 30 and 45 minutes, the myocardial ischemia-reperfusion model was established by loosening the ligature for 24 hours. At the same time, electrocardiogram was performed before, 5 min and 24 h after surgery. The ligation site was re-ligated 24 h after surgery, and Evan′s Blue-TTC double staining was performed to detect myocardial ischemic area and infarct area. Results: By 24 hours after surgery, the survival rate of mice was 90%, and the success rate of MIR modeling was 86.7%. Electrocardiogram showed that the ST segment and the T wave was elevated after LAD ligation, and the QRS wave was broadened, followed by the gradually decrease of the ST segment. After ligation of LAD, the ventricular wall below the ligature line showed grayish white, and the pale infarct area was observed 24 h after operation. The frequency and amplitude of heart beat were significantly weaker than before ligation. Cardiac sections were stained with Evan′s Blued-TTC to present a clearly defined ischemic, infarcted, and normal myocardial tissue. In ischemia 45 min+reperfusion 24 h group, the ratio of the ischemia area + infarction area to the total myocardial area of the left ventricle was（63.8±6.36）% and the ratio of the area of the infarct area to the area of the ischemic area + infarct area was （46.7±5.77）%. Conclusion: This new rapid and convenient method of I/R in mice may be a more efficient model of MIR. It reduces the time required for the use of the ventilator, and the success rate of modeling is more than 85%.

［Key words］mouse； coronary artery ligation； ischemia reperfusion； animal model