The aim of this study was to evaluate the anti-inlfammatory effect of the extract of Zanthoxylum schinifolium on ulcerative colitis induced by 3% dextran sulfate sodium in the rat. The experiment animals were divided into six groups: control (normal), DDS-induced colitis, 1 mg/kg, 15 mg/kg and 150 mg/kg of the extract of Z. schinifolium and 150 mg/kg of 5-aminosalicylic acid (5-ASA) as comparative drug. Anti-ulcerative colitis effect was evaluated pathologically by disease activity index (DAI), the change of weight and myeloperoxidase (MPO) in colon mucosa. Treatment with 15 mg/kg and 150 mg/kg of the extract of Z. schinifolium significantly improved the gain of body weight and DAI as clinical symptoms, and reduced MPO and $PGE_2$ level as biochemical index. Especially, 150 mg/kg of the extract of Z. schinifolium showed markedly more improvement than the same dose of 5-ASA in all kind of index such as MPO, $PGE_2$ and DAI. These results suggest that Z. schinifolium mediated anti-inflammatory action on colorectal sites may be a useful therapeutic approach to ulcerative colitis.