Abstract: Furazolidone in relatively small doses(i. e., 20～50 mg/kg) was found to be an effective anti-ulcer agent in three experimental gastric ulcer models in rats, namely, the acetic acid-induced chronic ulcer, indomethacin-induced and pyloric ligation induced ulcers. Among these, the indomethacin-induced ulcer was particularly markedly inhibited. In addition, a decrease of pepsin activity, an increase of hexosamine level and, in larger doses, a decrease of volume of gastric juice collected from pyloric-ligated stomaches were also observed. However, the drug was shown to be ineffective against the stress-restraint ulcer model.The above characteristic pattern of furazolidone action on various animal ulcer models was found not to be shared by known anti-ulcer drugs such as carbenoxolone, atropine, cimetidine and doxepin. Furazolidone and carbenoxolone showed synergistic effects on the pyloric ligation model. Therefore, it would be advisable to use a combination of subtherapeutic doses of both drugs in clinical gastric ulcer therapy, in expectation of obtaining better efficacy and fewer adverse effects.