The bark of Ulmus davidiana var. japonica(Ulmaceae) has been described in traditional books to have diuretic and laxative actions, to ameliorate edematous disease, and to be used in insomnia and gastointestinal disorders. Thus this study was carried out to elucidate some of the pharmacological activities of the plant extracts. The results obtained in tills experiment indicated that its methanol extract elicited remarkable inhibition of HCI.ethanol induced gastric lesion, Shay ulceration and gastric secretion. However, it showed no anti-inflammatory action. The acute toxicity of the extract was low, that is, the minimum lethal dose was more than 2000 mg/kg by oral administration in mice. The systematic fractionation of the methanol extract by hexane, ether, ethylacetate and butanol resulted in potent prevention of gastric erosion in butanol and water fractions.