Recent advances in endoscopic diagnosis and treatments have increased the number of early gastric carcinomas being treated by endoscopic resection. However, the appropriate criteria for endoscopic resection of gastric carcinomas with submucosal invasion are not completely established. During the past 12 years from 1980 to 1992, 116 lesions in 116 patients were treated by surgical operation for differentiated type submucosal invasive gastric carcinoma. In this study, the risk factors of lymph node metastasis were investigated clinicopathologically. As the result, 1) Heterogeneity of submucosal invasive tumor margin was demonstrated in 19 (16%) of the 116 lesions of which predominant histology was differentiated adenocarcinoma. 2) Lymph node metastasis was demonstrated in 16 (16%) of the 97 lesions of which histology was differentiated type. 3) Significant risk factors of lymph node metastasis was demonstrated in submucosal massive invasion (sm3), papillary adenocarcinoma, INF gamma, lymph vessel involvement (ly(+)), and existence of ulcer (ul(+)). 4) Sm3 and papillary adenocarcinoma (pap) had a higher malignant potential than ly(+), INF gamma, and ul(+) by multivariate analysis using the logistic regression. 5) All lesions with both well differentiated adenocarcinoma (tub1) and sm minimal invasion (sm1) had no lymph node metastasis. These results suggested that the lesions with both well differentiated adenocarcinoma tub1 and sm1, which have no other risk factors such as ly(+), INF gamma, and ul(+), may be considered as the appropriate indication for endoscopic treatment of gastric submucosal carcinoma.