OBJECTIVE: To observe the effect of acupuncture stimulation of different acupoints or acupoint groups on intestinal locomotor in slow transit constipation (STC) mice, so as to provide experimental evidence for demonstrating the synergic function of acupoint combination. METHODS: A total of 190 Kunming mice were randomized into 19 groups:normal control, model, uni-"Quchi" (LI 11), uni-"Shangjuxu" (ST 37), uni-"Tianshu"(ST 25), and uni-"Dachangshu"(BL 25) groups, for analyzing the effect of single acupoint; normal control, model, uni-ST 25+uni-BL 25, uni-LI 11+uni-ST 37, bi-ST 25, bi-BL 25, bi-LI 11, and bi-ST 37 groups, for comparing the effect between single acupoint and two acupoints combination; normal control, model, bi-ST 25+bi-BL 25, bi-LI 11+bi-ST 37, and uni-LI 11+uni-ST 37+uni-ST 25 +uni-BL 25 groups, for comparing the effect between four acupoints and two acupoints combinations (10 mice/group). The STC model was established by intragastric administration of compound diphenoxylate suspension (1 mg/100 g), once daily for 2 days. Manual acupuncture needle stimulation (200 twirling times/min for 1 min) was applied to the abovementioned unilateral or bilateral acupoints twice daily for 7 times. The first defecation time, the defecation grain number in 12 h and the intestinal propulsion rate were determined using activated carbon gavage. RESULTS: Compared with the normal group, the first defecation time was significantly increased in the STC model group (<0.01), while the 12 h defecation grain number and the intestinal propulsion rate were considerably decreased in the model group (<0.01). After manual acupuncture intervention, the first defecation time was notably shortened in the uni-LI 11, uni-ST 37, uni-ST 25, uni-BL 25, bi-ST 25, bi-BL 25, bi-LI 11, bi-ST 37, uni-ST 25+uni-BL 25, uni-LI 11+uni-ST 37, bi-ST 25+bi-BL 25, bi-LI 11+bi-ST 37 and the uni-ST 25+uni-BL 25+uni-LI 11+uni-ST 37 groups compared with the model group (<0.05), while both the 12 h defecation grain number and intestinal propulsion rate were considerably increased in the abovementioned 13 acupuncture groups (<0.05, <0.01). The effects of uni-ST 25+uni-BL 25 and uni-LI 11+uni-ST 37 were significantly superior to those of bi-ST 25, bi-BL 25, bi-LI 11 and bi-ST 37 groups, and those of the uni-ST 25+uni-BL 25+uni-LI 11+uni-ST 37 group were markedly superior to those of bi-ST 25+bi-BL 25 and bi-LI 11+bi-ST 37 groups in shortening the first defecation time and in increasing the 12 h defecation grain number and intestinal propulsion rate (<0.05). CONCLUSIONS: Acupuncture stimulation of LI 11, ST 37, ST 25 and BL 25 can improve constipation in STC mice, and the effect of two acupoints combination is significantly superior to that of the corresponding bilateral single acupoint, and that of the 4 unilateral single acupoint combination is obviously superior to that of two bilateral acupoints combination, suggesting a synergistic action of acupuncture stimulation.