Objectives : Ulcerative colitis (UC) is an inflammatory bowel disease, which is one of chronic gastrointestinal disorders. Orostachys japonicus (OJ) has been used as a traditional medicine for various diseases including gastric cancer, gastric ulcers and intoxication. However, the regulatory effect of OJ on intestinal inflammation has not been fully understood, yet. The aim of this study was to investigate the effect of OJ on dextran sulfate sodium (DSS)-induced colitis in mice. Methods : To ascertain the pharmacological effects of OJ, the colitis mice were induced by drinking water containing 5% DSS for 7 days. Mice were randomized into groups receiving OJ (100 mg/kg), sulfasalazine (150 mg/kg) as a positive control, or water as a negative control. We evaluated the effects of OJ on DSS-induced the clinical signs, measuring weight loss and colon length. In addition, the inhibitory effect of OJ on the tumor necrosis factor-${alpha}$ (TNF-${alpha}$) level was determined by enzyme-linked immunosorbent assay in colitis tissue. Results : The results indicated that mice treated with DSS showed remarkable clinical signs, including weight loss, and reduced colon length. However, treatment with OJ significantly improved the weight loss and DAI as clinical symptoms. Moreover, OJ reduced the TNF-${alpha}$ levels in DSS-treated colon tissues. Conclusions : Collectively, the findings of this study provide us with novel insights into the pharmacological actions of OJ as a potential medicine for use in the treatment of ulcerative colitis.