Objective To investigate the preventive effect of carbachol on the formation of postoperative intra-abdominal adhesion. Methods Forty-four Wistar rats were randomly divided into sham operation group (SO group, n=12), operation group (n=16) and carbachol treated group (carbachol group, n=16, carbachol 50 μg/kg). Animal model of abdominal adhesion was established by rubbing the procussus vermiformis of cecum with dry sterile gauze, and by clamping and scuffing abdominal wall. Half of rats were separately killed on day 7 and day 14 after surgery, respectively. The degree of adhesion was evaluated according to Phillips 5-scale grade and the feature of this model. The histopathological changes of adhesive tissues were observed and the content of collagen type Ⅰ in the tissues was detected by immunohistochemistry. Results The scores of intra-abdominal adhesion were significantly lower in the carbachol group than those in operation group both on 7 d and 14 d (P＜0.01). Mild inflammatory changes and less fibrous proliferation were observed in carbachol group microscopically. The contents of collagen type Ⅰ detected by immunohistochemistry were significantly lower in the carbachol group than those in operation group both on 7 d and 14 d (P＜0.01). There was no significant difference of the score of abdominal adhesion and content of collagen type Ⅰ in the same group between 7 d and 14 d (Pgt;0.05). Conclusion Carbachol may take a significant role in the prevention of postoperative abdominal adhesion in rat.