Anti-ulcerogenic activities of the 70% methanol extracts of Panax ginseng C.A. MEYER were examined in rats. The 70% methanol extracts were found to show inhibitory effects on the Shay-ulcer in pylorus-ligated rats, serotonin- and endotoxin-induced ulcer. Furthermore, in order to examine the mechanism of the 70% methanol extracts for the serotonin- and endotoxin-induced ulcer, the effects of the 70% methanol extracts on the gastric mucosal blood flow in rats were investigated. As a result, the 70% methanol extracts inhibited the decrease of gastric mucosal blood flow induced by serotonin and endotoxin.