¡¾Abstract¡¿AIM: To investigate the preventive effect of chitosan and allantoin against postª²surgical abdominal adhesions and to study the synergetic effects of these two drugs and discuss the mechanism. METHODS: Ninetyª²six rabbits were chosen to establish intestinal adhesion models, which were randomly and evenly divided into control group (group A)£¬chitosan treatment group (group B), allantoin treatment group (group C) and chitosan+allantoin treatment group (group D). Right after the operation, the situations of rabbits were observed. Then the rabbits were dissected to evaluate the degree of adhesions 1 and 2 weeks after the operation. Study the pathological changes under microscope. RESULTS: The models of adhesions were reliable. The adhesion degrees of group B, C and D were all significantly decreased compared with that of group A (P<0.05). Group D showed a better effect than group B and C (P<0.05). Group B, C and D could alleviate the inflammation reaction and the degree of fibrosis compared with group A. CONCLUSION: Treatment with chitosan and allantoin during operation could prevent postª²surgical abdominal adhesions, and the two drugs had a synergetic effect. ......