The invention relates to the technical field of medicine, and especially relates to a use of dencichine. The invention discloses the use of dencichine, prodrugs and pharmaceutical salts or plant extracts containing dencichine in preparation of drugs or health-care products for prevention or treatment of ulcerative colitis. The dencichine disclosed for the first time can significantly improve the experimental ulcerative colitis mice weight reduction, bloody stool, shortening of colon, tissue pathological damage and other symptoms, provides a new choice for clinical treatment of ulcerative colitis, and has a good application prospect.