The methanol extract of Taraxaci Herba was found to have inhibitory effect on the gastric lesion induced by HCl-ethanol. The systematic fractionation of the methanol extract resulted in positive action with water fraction in the gastric lesion. It also showed significant inhibition of gastric lesion induced by HCl-aspirin and absolute ethanol, but did not prevent indomethacin induced gastric lesion. This fraction did not affect basal gastric acid secretion but showed a decrease of pepsin activity in pylorus-ligated rats.