We histologically investigated 207 cases with the depressed type intramucosal cancer of the stomach, as to the risk factor of ulcer formation in the cancer (Ul.), tumor size of less than and not less than 10 mm, histological type of differentiated carcinoma (Diff.) and undifferentiated carcinoma (Undiff.), tumor location classified by the usually occurring region of the peptic ulcer (Usual portion and Unusual portion) and the intramucosal propagations of extensively vertical type (EV) and nonextensively vertical type (NV). Result : 1) Tumor size, histological type, tumor location and intramucosal propagation type were significantly related to Ul., as the result of multivariate analysis. 2) The frequency of Ul. at the lesions of these cases, regardless of histological type, was higher at the lesion of Usual portion than at Unusual portion. And the frequency of Ul., independently of tumor location, was higher in Undiff. than in Diff.. 3) The frequency of Ul. at the lesions of Unusual portion in Undiff. was higher in EV than in NV. Conclusion : We suggested that extensively vertical propagation type of intramucosa, as well as large tumor size, Undiff. and at the lesion of Usual portion, was a significant risk factor for Ul. of the depressed type intramucosal cancer of the stomach. 2) We concluded that the intramucosal propagation type of the cancer was particularly concerned with Ul. at the intramucosal lesion of Unusual portion in Undiff.