Objective To determine the effectiveness of sodium hyaluronate (SHA) in preventing intraperitoneal (IP) adhesion. Methods Thirty-eight rats were randomly divided into A,B,C groups, normal saline, 6% Dextran-40 or SHA were applied on the present serosal injury respectively, during operation. Biopsy was taken on the 14th postoperative day.Results There were statistically significant differences in the extent of adhesion among three groups (Ｐ＜0.01). Mild inflammatory changes and less fibrous proliferation were found in group C by microscopy and decreased production of collagen (by fibroblast) and active mesothelial cells proliferation were observed in group C under electron microscope. Conclusion SHA appeares to reduce the extent of postoperative IP adhesion, which is more satisfactory than Dextran-40.