This study was done to investigate the clinical effects of Daegunchungtang on the peptic ulcer and the function of gastointestinal tract. The liquid extracts of Daegunchungtang was administerd orally to the rats and mice. Then the effects of isolated ileum, pylorus-ligated and indomethacine-induced ulcer, gastric juice secretion, and transport abilities of the small and large intestine, were studied. The following results have been obtained : 1. Daegunchungtang showed to have an inhibitory effects on the smooth muscle contraction of the isolated ileum by acetylcholine chloride and barium chloride. 2. Daegunchungtang showed to have an inhibitory effect on the contraction of the gastric fundus-strip by acetylcholine chloride and barium chloride. 3. The preventive effects were recognized on the pylorus-ligated ulcer, by administration of Daegunchungtang. 4. The preventive effects were recognized on the indomethacine-induced ulcer, by administration of Daegunchungtang. 5. The Inhibitory effects on the secretion gastric juice, free & total acidity, and pepsin-output were recognized, by administration of Daegunchungtang. 6. The transport abilities in the small intestine were increased, by administration of Daegunchungtang. 7. The transport abilities in the large intestine were not recognized, by administration of Daegunchungtang. According to the above results, it is considered that the experimental effects of Daegunchungtang has correspond to the oriental medical literatures.