It has long teen known in herbal medicine that the mugwort not only exerts a strong hemostatic and parasiticidal actions but also has therapeutic effects for stomachache and diarrhea. In recent pharmaceutical botany the mugwort is known to have antipyretic and astringent actions also. Among the major principles which have been found in the leaves and stems of mugwort are inulin, alkaloids, vitamines, and esestial oil. It is well known that santonin, one of the well known parasiticides, is one of the glucosides extracted from the limited species of mugwort. The present study was undertaken to investigate effects of mugwort(Artemisia asiatica Nakai) on the motility of isolated rabbit duodenum. The results obtained are as follows: At does of 0.2%, 0.5% and 1. 0% AAJ(Artemisia asiatica juice) markedly enhanced contractility of isolated duodenum and tonus of the intestine was also augmented with doses of 0.5% and 1.0%. The augmentative effect of AAJ on intestinal motility was not affected by pretreatment with epinephrine and avil while it was completely abolished by atropine. Therefore it is strongly suggested that augmentative action of AAJ on duodenal motility was exerted solely through muscarinic cholinergic receptors.