Objective：To study the risk factors of patients with premature ST-segment elevation myocardial infarction（STEMI） and investigate the correlation between neutrophil gelatinase-associated lipocalin（NGAL） and premature STEMI and its clinical value in the prognosis assessment. Methods：Totally 166 patients diagnosed as premature STEMI from Jan 2017 to Dec 2018 were selected and followed up for 12 months，and 171 patients underwent coronary angiography during the same period with lumen stenosis <50% were selected as the control group. The risk factors of major adverse cardiac events（MACE） occurrence in premature STEMI patients were analyzed. Receiver operating characteristic（ROC） curve was used to find the optimal cutoff point for predicting the occurrence of MACE. Results：NGAL levels were significantly higher in premature STEMI group than those in control group（P < 0.05）. NGAL levels were significantly higher in MACE group compared with non-MACE group（P < 0.05）. Multivariate logistic regression analysis showed that NGAL was independently associated with MACE occurrence in premature STEMI patients（P < 0.05）. ROC curve of NGAL in predicting the occurrence of MACE showed that the area under curve of NGAL were 0.897（P < 0.05）. Conclusion：NGAL levels which were significantly elevated in premature STEMI patients are positively related with MACE occurrence. Thus NGAL can be used as a predictor of prognosis assessment in premature STEMI patients.