Objective: To evaluate recent prognosis of patients with acute ST elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI), and explore related risk factors.Methods: Clinical data of 168 STEMI patients undergoing primary PCI were retrospectively analyzed.According to occurrence of major adverse cardiovascular events (MACE) within 30d or not, they were divided into poor prognosis group (n=40) and good prognosis group (n=128).Clinical data were compared between two groups.Logistic regression analysis was used to analyze independent risk factors for MACE.Results: Incidence rate of MACE was 23.81% among the 168 STEMI patients.Logistic regression analysis indicated that age (OR=1.326, 95%CI 1.168~1.505), family history of coronary heart disease (OR=1.852, 95%CI 1.369~2.505), number of diseased vessels ≥2 (OR=1.682, 95%CI 1.382~2.047), Killip′s class Ⅲ~Ⅳ (OR=1.693, 95%CI 1.428~2.007) and onset-to-PCI time (OR=1.785, 95%CI 1.425~2.236) were the independent risk factors, P<0.01 all;TIMI grade 3 (OR=0.623, 95%CI 0.518~0.749) and tirofiban application (OR=0.452, 95%CI 0.367~0.557) were independent protective factors for MACE, P<0.01 both.Conclusion: Advanced aged, family history of coronary heart disease, number of diseased vessels ≥2, poor cardiac function and long onset-to-PCI time are independent risk factors, while TIMI grade 3 and tirofiban application are independent protective factors for MACE.