Ulcerative colitis, a diffuse inflammatory disease of the mucosal lining of the colon and rectum, is characterized by bloody diarrhea that waxes and wanes without apparent cause. In oriental medicine, Jakyaktang has been used to treat the disease, diagnosed as Damp-Heat dysentery. We prescribed Jakyaktang-gamibang to two patients who had suffered from ulcerative colitis diagnosed as Damp-Heat dysentery. The two patients were treated with Jakyaktang-gamibang and improved in consciousness of symptoms. We suggest that oriental medicine therapy is effective for treatment of ulcerative colitis.