Objective : his study was carried out to investigate the effect of Dansameum (DS) on the gastrohemorrhagic lesion induced by ammonia in rats. Methods : Rats were pretreated with DS extract 25 mg/kg for 10 days and then were given amonia through gastric tube. The animals were killed 1 hr after amonia treatment. Results : DS extract siginificantly reduced the gastrohemorrhagic lesion score, the gastric lipid peroxide level, the gastric urease activity, the gastric myeloperoxidase activity, the gastric acid phosphatase activity, xanthine oxidase activity and type conversion, and increased the gastric glutathione level considerably. In photomicrographs of stomach tissue in rat, we could see the gastrohemorrhagic lesion induced clearly. conclusions : These results suggest that DS extract may be effective in peptic ulcer.