lcerative colitis (UC) is a chronic, idiopathic inflammation of the large intestine (colon), which is classified as a form of inflammatory bowel disease. The incidence of UC has been increasing around the world. In patients with UC, ulcers and inflammation of the inner lining of the colon could incur symptoms of abdominal pain, diarrhea, and rectal bleeding. Abnormal activation of the immune system, hereditary susceptibility and alteration of intestinal flora caused by mucosal barrier defects may play a role in the pathophysiology of UC. MSCs have shown therapeutic effects in various inflammatory diseases due to its hypo-immunogenic and immunoregulatory properties. MSCs could regulate innate and adaptive immune responses by releasing various mediators, including immunosuppressive molecules, growth factors, exosomes, chemokines, complement components, and multiple metabolites, when exposed to inflammatory environment, thus promoting the repair and regeneration of damaged tissues. Bone marrow-derived MSCs played a main role in repairing injured intestinal mucosa, as well as downregulating the immune function of T cells.