Abstract: ObjectiveTo study the pathological relative risk factors of postoperative radiation in gastric cancer after radical gastrectomy for clinic. Methods From Feb 2004 to Jan 2006, a total of 110 patients with newly diagnosed stomach carcinoma were enrolled in this study.All patients underwent gastrectomy with D1/D2 lymph node dissection and had complete postoperative pathologic analysis.Pathologically, all patients were confirmed with R0 disease.Univariate analysis was applied on the pathologic information and multivariate analysis was applied based on the univariate analysis. Results (1)Univariate analysis revealed that tumor diameter，histology，vascular invasion，lymphatic vessel invasion and neural invasion were correlated with T/N classification.Multivariate analysis revealed that vascular invasion and lymphatic vessel invasion were associated with T classification and lymphatic vessel invasion was associated with N classification.(2) For T and N classifications, lymphatic vessel invasion was strongly relevant factor. Conclusion For T and N classifications, lymphatic vessel invasion was strongly relevant factor.For patients with pathologically confirmed lymphatic vessel invasion, postoperative adjuvant radiotherapy is recommended.