〔Abstract〕 Objective To analyze the risk factors influencing postoperative survival of patients with resected gastric adenocarcinoma and stablish a prognostic Nomogram model. Methods The clinicopathological and survival data of 4787 patients with resected gastric adenocarcinoma were collected from the National Cancer Institute′s Surveillance,Epidemiology and End-results(SEER) database.ROC curve was used to determine the optimal cut-off point of lymph node ratio(LNR).The Kaplan-Meier method was used to calculate the cumulative survival rate,and the significant difference was evaluated by the Log-rank test.The Cox multivariate regression analysis was applied to evaluate the independent prognostic factors,and a prognostic Nomogram was established by these independent prognostic factors.Then the Harrell′s C-index and decision curve analysis(DCA)were used to estimate the accuracy and clinical utility of the Nomogram system. Results The optimal cutoff value of LNR was 0.075.Univariate and multivariate analysis showed that LNR,AJCC 7 th T stage, N stage, M stage were independent prognostic factors of patients with resected gastric adenocarcinoma(P<0.05). Using these factors to build the Nomogram prognosis model, the internal verification C-index was 0.708(95%CI:0.696～0.720) and the consistency of calibration curves was rather good. The Nomogram system showed good accuracy in predicting OS of 1-year,3-year. DCA also showed that the Nomogram prediction model had higher clinical benefit than the AJCC 7 th TNM system. Conclusion Age, LNR, AJCC 7 th T stage,N stage,and M stage are independent prognostic factors of patients with resected gastric adenocarcinoma(P<0.05).The Nomogram provided improved discrimination and higher clinical benefit than the AJCC 7 th TNM system.