Objective To observe the therapeutic effects and action mechanism of moxibustion in the treatment of intestinal fibrosis in ulcerative colitis. Methods Tianshu (ST 25) and Qihai ( CV 6) were the main acupoint; other points were used according to syndrome differentiation. Sixty-five patients were randomized into two groups: Group A in which 32 cases were treated by herbpartitioned moxibustion and group B in which 33 cases were treated by bran-partitioned moxibustion. The therapeutic effects and TGF-β1, Ⅰ and Ⅲ collagen expressions were measured before and after treatment. Results In group A, 17 cases were cured, 12 cases improved and 3 failed; in group B, 1 1 cases were cured, 16 cases improved and 6 cases failed. Ⅰ , Ⅲ collagen expressions were obviously inhibited in the two groups, in group A in particular. Conclusion In the prevention and treatment of intestinal fibrosis, moxibustion may reduce the expression of TGF-β1, and hence to block or inhibit the synthesis of Ⅰ、Ⅲ collagens, and improve the structure and function.