In order to clarify the therapeutic meaning of sympathetic innervation or denervation in various methods of selective vagotomy, two procedures without and with cutting off supplying vessels and sympathetic nerve in the lesser curvature (SV1 and SV2) were compared with each other from the point of gastric circulation, secretion, and gastric mucosal defensive system. Gastric blood flow in the body near the lesser curvature was measured by the hydrogen gas desaturation method, and morphological observation of the microcirculation in the gastric wall was performed by the dry ice methanol wintergreen method (D.M.W. method), Then, gastric secretion test was carried out under tetragastrin stimulation, using fifteen dogs with a gastric fistula. Furthermore, hexosamine contents in the gastric mucosa was assayed according to the Boas' method. As a result, the following conclusions were drawn. It was suggested that sympathetic innervation of the stomach may be a primary cause of reduction in gastric blood flow through predominant sympathetic innervation at the acute stage after vagotomy, on the other hand, at the chronic stage after vagotomy, it shows suppressive effects on gastric secretion, and SV1 procedure of selective vagotomy was considered to be more rational surgical procedure for peptic ulcer than SV2.