Abstract: OBJECTIVE To observe the effect and mechanism of Tongbian Decoction on slow transit constipation Model. METHODS SD rats were divided into normal control group and model group. Normal control group were given distilled water， while the model group was treated by laxative colon method and divided into natural recovery group， mosapride groups and Tongbian Decoction soup. After the drug intervention of 2， 4 and 6 weeks， dejection amounts in colon， the rate of carbon powder proposed， colonic electrical test and the morphological observation of colon interstitial cells of Cajal (ICC) were measured. RESULTS Compared to natural recovery group，Tongbian Decoction group significantly alleviated the constipation symptoms of functional constipated rats， enhanced the contraction of colon tissue， promoted intestinal peristalsis and improved the damaged intestinal tissue cells (P<0.01). CONCLUSION Tongbian Decoction can promote the colonic transit activities of slow transit constipation model rats.