Objective:To observe anti-apoptotic effect of insulin,and explore the role of Bad in anti-apoptotic mechanism of insulin during post-ischemia reperfusion injury in myocardium of rats. Methods:Forty-six male Sprague-Dawley rats were randomly divided into 4 groups:①I/R group was subjected to ischemia for 30 min and reperfusion for 180 min;②INS group was subjected to intravenous infusion of Insulin(60 U/L,4 ml/kg·h) at 5 min before 3 h of reperfusion;③INS+LY group was subjected to intravenous infusion of LY294002(0.3 mg/kg) at 10 min before 3 h of reperfusion and intravenous infusion of insulin and LY294002(30 -滋g·kg-1·h-1) at 5 min before 3 h of reperfusion;④SHAM group was subjected to placing a silk around the left anterior descending coronary artery without a slipknot. At the end of 4 h of reperfusion,apoptosis of cardiomyocytes were assessed through TUNEL and DNA Ladder;Immunochemistry and Western-blotting were used to analyse the expression of phosphorylated Bad in all groups. Results:①Compared with I/R group,apoptosis index(AI) were significantly decreased,and expression of phosphorylated Bad was prominently higher in INS group. ②There were a remarkably increase in AI and lower expression of phosphorylated Bad in INS+LY group than that in INS group. Conclusion:①Ischemia and reperfusion resulted in lower expression of phosphorylated Bad in myocardium of rats;②Insulin exerted an anti-apoptotic effect in myocardium of rats during ischemia and reperfusion;③its mechanism may be involved in higher expression of phosphorylated Bad via PI3-K/Akt pathway.