Endoscopic therapy has been aggressively used for radical treatment of early gastric cancer, because endoscopic resection allows us to collect the removed tissue and to determine histopathologically whether the cancer lesion has been completely resected. In order to succeed in radical treatment, the complete resection of lesion and no lymph node metastasis are necessary. On the basis of thorough histopathological investigations into operated cases with early gastric cancer, the types of early gastric cancer which have no lymph node metastasis are considered to be as follows: 1) Intramucosal carcinoma type I type II a, measuring 30 mm or less type II b type II c, measuring 10 mm or less 2) carcinoma invading up to submucosal layer type II a + II c, measuring 10 mm or less type II a, measuring 20 mm or less type II b type II c, measuring 10 mm or less type II a + II c, measuring 10 mm or less However, indications of endoscopic resection should be more strictly decided due to diagnostic and technical problems. Eventually, it will be important to detect and resect intramucosal gastric carcinoma as small as possible in order that the lesion be completely resected. The success of curative treatment is evaluated by not only histopathological examination of resected tissue, but also through follow-up study. Therefore, various problems remain to be resolved in this treatment. A larger case sampling will serve to confirm the reliability of this form of therapy for early gastric cancer.