The difference of stability was compared between the aqueous extract of Puerariae radix MTF-101 [57455-79-5], was much more resistant to cholinesterase [9001-08-5] and high temperature, and more effective on the intestinal movement of anesthetized guinea pig and intestinal internal pressure than acetylcholine chloride [60-31-1] (1 × 10-7 g/ml).