To observe the effect of acupuncture on intestinal motility in normal, diarrhea and constipation model rats, so as to explore the underlying mechanism of bidirection regulation of acupuncture at ST25.Methods:Sixty anesthetized SD rats were randomized into normal group, diarrhea group and constipation group (20 in each group). Rat model of constipation was constructed by intragastric infusion of ice water, and rat model of diarrhea was constructed by intragastric infusion of folium sennae. The intestinal contractility was recorded with manometric balloons put into the jejunal and distal colonic lumens. Acupuncture was applied to unilateral ST 25 (Tianshu). The needle was rotated clockwise and anti clockwise at 2 Hz for 60 s. Results: The mean frequency and amplitude of jejunum motility during acupuncture at ST25 were significantly decreased compared to baseline both in normal and diarrhea model rats (P<001,P<001）. Whereas for distal colon, the mean frequency and amplitude were significantly increased by acupuncture at ST25 both in normal and constipation model rats (P<001,P<005). Conclusion: The results of the present study suggest that acupuncture at ST25 induces bidirection regulations, as inhibitory effect in jejunum and excitatory effect in dinstal colon, via somato sympathetic excitation and sacral parasympathenic excitation.