Abstract: 1. Infusions of Corydalis ambigua exerted no noticeable effect on the isolated intestines of rabbits and rats, but induced temporary excitation on preparations of guinea pig intestine. 2. For isolated preparations of rabbit, guinea pig and the rat intestines, if spasm had been induced by acetylcholine, pilocarpine, and barium chloride, subsequent applications of infusions of Corydalis ambigua caused anti-spasmodic effects. 3. Infusions of Corydalis ambigua, injected intravenously, brought about temporary excitation on the animal intestines in situ. This excitation could not be dissipated either by application of diphenhydramine, ganglionic blocking agents or atropine, or by bilateral vagotomy. 4. Infusions of Corydalis ambigua at a dose equivalent to 10g. of Corydalis did not seem to produce any prominent effect on the gastro-intestinal movement in normal human adults.