This study was undertaken to determine the effects of Zusanli(ST 36) electro-acupuncture(EA) on the small intestinal motility in rat. The motor activity of the rat small intestine was evaluated by intestinal transfortation rate. Changes in the motility in vivo of ileum was measured before and 10 minutes after acupuncture. In order to examine whether EA effect was affected by stimulated duration and left or right sides of ST36 acupoint, both of the difference effects of left or right sides on acupoints of ST 36 and the stimulated duration of 10, 20, 30 min. were investigated on the motility in vivo of ileum. These results suggest that effect of Zusanli(ST36) for increasing the small intestinal motility should stimulate more than 20 minutes, left ST36 EA has stronger effect than right ST36 EA.