Objective: To investigate the factors of spontaneous recanalization (SR) and its impact on long-term prognosis in patients with STEMI. Methods: The study consecutively enrolled patients diagnosed with STEMI and underwent primary percutaneous coronary intervention in Nanjing First Hospital from July 2011 to April 2019. Patients were divided into the SR group (TIMI flow grade 0-1) and the Non-SR group (TIMI flow grade 2-3) based on the results of coronary angiography. The data of the two groups were collected, including general clinical data, laboratory test results, coronary angiography and drug treatment. The primary endpoint was all-cause death. Results: 1124 patients were enrolled, including 272 patients(24.2%) in the SR group and 852 patients (75.8%)in the Non-SR group. Patients with SR had significantly lower proportions of hypertension, CK-MB peak value, creatinine levels, uric acid levels, thrombus vessel aspiration rate, IABP implantation, and in-hospital mortality compared to the non-SR group. However, The left ventricular ejection fraction was higher in the SR group than in the non-SR group. Multivariate Logistic regression analysis showed that hypertension was a disadvantage for SR.(OR=0.744,95%CI 0.561-0.985, P=0.039). The mean follow-up period is 75±32 months, during which 124 patients occurred all-cause mortality. Kaplan-Meier curves indicated that no significant difference in all-cause mortality between the SR group and the non-SR group(8.8% vs. 11.7%, log-rank P=0.182). Multivariate COX regression analysis revealed that age, Killip classification, creatinine, in-hospital IABP implantation, left ventricular ejection fraction, single-vessel disease, ticagrelor and β-blocker were independent predictors of all-cause death in STEMI patients. Conclusions: 24.2% of STEMI patients occurred SR before the primary percutaneous coronary intervention. Hypertension was found to be an unfavorable factor for SR occurrence. However, long-term follow-up revealed that SR did not reduce all-cause mortality in STEMI patients.