OBJECTIVE： To evaluate the effects of Sennae Folium combined with mannitol for bowel cleaning on multi-slice spiral CT bowel imaging. METHODS： 52 patients receiving multi-slice spiral CT imaging examination in our hospital during Jun. 2011 to Jun. 2012 were collected retrospectively， and then divided into control group （22 cases） and observation group （30 cases） according to the methods of bowel preparation. Both groups fasted for 12 h before examination. Sennae Folium 20 g soaked in boiled water 500 ml for half an hour was given to patients in control group 12 h before examination， and then was soaked in boiled water 500 ml again for drinking and other pure water 1 000 ml was also given to patients. Sennae Folium 10 g soaked in boiled water 500 ml was given to patients in observation group 1 d before examination and 2 h after breakfast； soaked in boiled water 500 ml again 2 h after lunch； 10％ mannitol 500 ml and pure water 1 000 ml were given to patients after supper. Both groups received multi-slice spiral CT bowel imaging until the patients defecated watery stool after medication. The effective rate of bowl cleaning， image quality and the incidence of ADR were compared between 2 groups. RESULTS： The effective rate of bowel cleaning was 100％ in observation group， which was significantly higher than that of control group （81.82％）， with statistical significance （P＜0.05）. The excellent and good rate of imaging quality was 96.67％ in observation group， which was significantly better than that of control group （81.82％）， with statistical significance （P＜0.05）. The incidence of ADR as abdominal distension， nausea， intestinal mucosa damage in observation group were significantly lower than those of control group， with statistical significance （P＜0.05）. CONCLUSIONS： Sennae Folium combined with mannitol is effective method to prepare enteric multi-slice spiral CT imaging examination， and perform good bowl cleaning effect， high image quality and low incidence of ADR.