Abstract： Background::Reperfusion therapy is fundamental for ST-segment elevation myocardial infarction (STEMI). However, the details of contemporary practice and factors associated with reperfusion therapy in China are largely unknown. Therefore, this study aimed to explore reperfusion practice and its associated factors among hospitalized patients with STEMI in China.Methods::Patients with STEMI who were admitted to 159 tertiary hospitals from 30 provinces in China were included in the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome project from November 2014 to December 2019. The associations of the characteristics of patients and hospitals with reperfusion were examined using hierarchical logistic regression. The associations between therapies and in-hospital major adverse cardiovascular events were examined with a mixed effects Cox regression model.Results::Among the 59,447 patients, 37,485 (63.1%) underwent reperfusion, including 4556 (7.7%) receiving fibrinolysis and 32,929 (55.4%) receiving primary percutaneous coronary intervention (PCI). The reperfusion rate varied across geographical regions (48.0%-73.5%). The overall rate increased from 60.0% to 69.7% from 2014 to 2019, mainly due to an increase in primary PCI within 12 h of symptom onset. Timely PCI, but not fibrinolysis alone, was associated with a decreased risk of in-hospital major adverse cardiovascular events compared with no reperfusion, with an adjusted hazard ratio (95% confidence interval) of 0.64 (0.54,0.76) for primary PCI at <12 h, 0.53 (0.37,0.74) for primary PCI at 12 to 24 h, 0.46 (0.25,0.82) for the pharmaco-invasive strategy, and 0.79 (0.54,1.15) for fibrinolysis alone.Conclusions::Nationwide quality improvement initiatives should be strengthened to increase the reperfusion rate and reduce inequality in China.Trial registration::www.ClinicalTrials.gov, NCT02306616