【Abstract】 Objective To investigate the shortterm efficacy of threedimensional conformal radiotherapy combined with concurrent chemotherapy in advanced gastric cancer after resection and prognosis. Methods The clinical data of 102 patients with gastric cancer underwent radical gastrectomy (D2 lymphadenectomy, R0, R1，Of these, 45 were R0 and 57 R1) from March 2010 to May 2014 were retrospectively analyzed. According to the different methods of postoperative radiotherapy, the patients were divided into observation group (using threedimensional conformal radiotherapy combined with concurrent chemotherapy) and control group (chemotherapy alone). The shortterm therapeutic efficacy and adverse reaction were compared between the two groups and the Cox regression model To explore the factors that affect the prognosis of patients. Results The total effective rate and tumor control rate in the observation group were higher than those in the control group(P＜005). The survival rate was 3 years , the median OS time , the disease had no 3year survival rate, the median PFS time(P＜005), respectively, compared with the control group. Adverse reactions were mostly grade ⅠⅡ, grade Ⅲ adverse reactions were similar, and all patients during the treatment did not appear 4 adverse reactions and chemotherapyrelated deaths. The prognosis of patients with advanced gastric cancer after radical resection was significantly higher than that of control group (P＜005). Conclusion Threedimensional conformal radiotherapy combined with concurrent chemotherapy can improve the shortterm therapeutic effect and prolong the life time, and the histological grade is low. The lymph node metastasis, tumor control rate is poor. EOCG High score is an independent prognostic risk factor for prognosis of patients with advanced gastric cancer after radical resection.