Aim Patients with ST-elevation myocardial infarction (STEMI) were subjected to administer ischemic post-conditioning (IPOC) before conducting emergency treatment with percutaneous intervention (PCI). Changes in serum soluble apoptosis factor (sFas) and soluble apoptosis factor ligand (sFasL) and the left ventricular ejection fraction (LVEF) under echocardiography during the 1 postoperative year were investigated in patients, and changes in cardiac function in patients and the possible mechanisms were explored. Methods 90 patients with acute STEMI who underwent emergency PCI were randomly divided into three groups before treatment:routine PCI group, IPOC 45 s group and IPOC 60 s group. No intervention was given within 3 minutes after reperfusion of infarct-related artery (IRA) in routine PCI group. Within 1 minute after the opening of IRA, repeated low pressure (4～6 standard atmospheric pressure) filling and retraction of the balloon were performed at the upstream of the patient's blood vessels for 3 times, each time lasting 45 s. The operation method of the IPOC 60 s group was the same as that of the IPOC45 s group, lasting 60 s each time. The levels of serum sFas and sFasL were measured before operation and 0 h, 24 h and 48 h after operation, and the changes of LVEF in the three groups were followed up for 1 month, 3 months, 6 months and 1 year. Results There was no significant difference in serum sFas, sFasL level among the three groups before operation and 0 h, 24 h after operation (all P＞0.05). 48 hours after operation, the serum sFas, sFasL level decreased significantly in the IPOC 60 s group and the IPOC 45 s group compared with the routine group (all P＜0.05). There was no significant difference in LVEF values among the three groups at 1 week, 1 month and 3 months after operation(all P＞0.05), but at 6 months after operation, the values of LVEF in IPOC 60 s group and IPOC 45 s group were higher than those in routine group. One year after operation, the value of LVEF in IPOC 60 s group was higher than that in routine group(P＜0.05). Conclusion Ischemic postconditioning 60 s reperfusion therapy after ischemia can significantly improve cardiac function in STEMI patients, and the mechanism may be related to the inhibitory effect of IPOC on apoptosis induced by myocardial reperfusion.