〔Abstract〕 Objective To evaluate the prognostic value of infarcted zone Tp-ec and Tp-e/QT in patients with St-segment elevation myocardial infarction. Methods A retrospective analysis was made of 281 patients diagnosed as STEMI. Among them, 36 were in the main adverse cardiac events(MACE) group and 245 were in the non-MACE group. The differences of Tp-ec and Tp-e/QT values before and after percutaneous coronary intervention(PCI) were compared between the two groups. The risk factors and predictors of MACE in STEMI patients were screened by binary Logistic regression analysis and ROC analysis. Results Compared with non-MACE group, MACE group had higher age, faster heart rate, longer door-to-balloon time, higher proportion of women and multiple vessel lesions, lower TIMI blood flow grade 3 ratio and lower left ventricular ejection fraction(LVEF). Univariate analysis showed that the Tp-ec and Tp-e/QT values of MACE group before and after PCI were higher than those of non-MACE group(P<0.05). Multivariate binary Logistic regression analysis showed that Tp-e/QT(OR=1.238,P<0.001), LVEF(OR=0.924,P=0.005) and door-to-balloon time(OR=1.007,P=0.018) were independent risk factors for MACE in STEMI patients before PCI. The area under ROC curve(AUC) was 0.817(95%CI0.763～0.864) and 0.889(95%CI0.843～0.926) respectively. Z test showed that the AUC of preoperative Tp-e/QT was significantly different from that of preoperative Tp-ec, postoperative Tp-ec and postoperative Tp-e/QT(P<0.05). Conclusion Preoperative Tp-e/QT is an independent risk factor for nosocomial MACE in STEMI patients. Preoperative Tp-ec and Tp-e/QT have higher predictive value for MACE.