Objectives : This study was carried out to investigate the effects of Soyumjungjang-tang(SJT) on the experimental ulcerative colitis induced by dextran sulfate sodium(DSS) in mice. Methods : Ulcerative colitis was induced through supplying 4% DSS solution as the drinking water for 7 days in 6-week-old male ICR mice. The colitic mice were divided into three groups: the sample groups were orally administered SJT in doses of 25mg/kg(S25 group) or 100mg/kg(S100 group) once a day for 10 days, from 3 days before starting drinking the DSS solution, and the control(C) group was administered normal saline instead of SJT. The DSS solution or SJT was not administered to the normal(N) group. The length of colon, histologic finding, the activities of myeloperoxidase(MPO) and alkaline phosphatase(AP), and the expressions of $IL-1{eta}$, IL-6, COX-2, $NF-{kappa}B$, and $I{kappa}B$ in colonic mucosa was checked using immunoblot, ELISA, etc. The activities of chondroitinase, tryptophanase, ${eta}-glucuronidase$ and ${eta}-glucosidase$ in stool were also measured. Results : The length of colon shortened, histologic finding deteriorated, the activities of MPO, AP, chondroitinase, tryptophanase, ${eta}-glucuronidase$ and ${eta}-glucosidase$, and the expressions of $IL-1{eta}$, IL-6, COX-2, $NF-{kappa}B$ increased, and the expression of $I{kappa}B$ decreased in the C group. All measures, except $NF-{kappa}B$, were restored in S25 group, but some measures deteriorated more in the S100 group than in the C group. Conclusions : According to the above results, it is supposed that SJT has a potential therapeutic effect on ulcerative colitis.