AIM:To observe the therapeutic effect of moxibustion on ulcerative colitis and its influence on the colonic mucosal morphology.METHODS:Forty-six patients with ulcerative colitis were randomly divided into the moxibustion with herbal medicine underneath group and the western medicine group. Thirty patients were treated with the above moxibustion and 16 patients with Salicylaye fapyridine (SASP).The colonic mucosa of 13 patients in the moxibustion group was observed by colonoscopy before and after the treatment. Mucin was also analyzed by H.E and AB-PAS staining.RESULTS:Seventeen patients were clinically cured,12 were improved and 1 unchanged in the moxibustion group. In the control group, 5 patients were clinically cured,7 improved and 4 unchanged. Thirteen patients with active UC were taken as the subjects for histopathologic analysis in this study. The colonic mucosal lesions were remarkably improved and the characteristic of the mucin also changed. In most sections, the chronic inflammation of mucosa was geatly ameliorated (P< 0.01). The inflammatory cell infiltratation much decreased and neutrophils, disapeared in most sections (P<0.001). The goblet cells significantly increased (P<0.001); crypt paracrypt abscess or mucosal ulceration was seen(P<0.001).CONCLUSION:The rate of cure of ulcerative colitis by moxibustion with herbal medicine beneath is superior to that by SASP. This sort of moxibustion can effectively improve the colonic mucosal lesions and restore the proportion of mucoprotein to near normal.