The indidence of the primary gastric lymphoma is reported to the range from 0. 5 to 8Fo of all malignant lesions of the stomach, of which reticulm cell sarcoma of t'he stomach is very rare. The tumor which is well responded to irradiation after surgical removal showed between survival than other gastric malignancies. We experienced a case of reticulum cell sarcoma which shov;ed a ulcer crater, po!ypoid tumor.; resembling carcinoma gastroscopically. The general concept of reticu!um cell sarcoma of the stomach with brief review of the !iterature is discussed here.