The first-line treatment strategy of moderate to severe UC was a important question at issue. The biological agents had potentiality to alter the disease course of UC. The AGA clinical guidelines had conditional recommend that IFX and other biological agene migtht be first-line therapy for high-risk UC patints but only had low grade evidence.We launched this multicenter prospective cohort trial to compare the efficacy and safety of infliximab (IFX) and corticosteroids(CS) when they was used as first-line therapy in UC patients.

Inclusion Criteria:

• moderately to severely active ulcerative colitis, defined as a total score of 6 to 12 on the Mayo scale (scores range from 0 to 12, with higher scores indicating more severe disease) and a subscore of at least 2 on the endoscopic component of the Mayo scale (subscores on each of the four components of the Mayo scale range from 0 to 3)
• Patients who had colonic involvement of at least 15 cm
• Patients who had a confirmed diagnosis of ulcerative colitis at least 3 months before screening and confirmed by Pathology

Exclusion Criteria:

• Patients who had previously used any TNF inhibitor
• Patients who were steroid-dependent or steriod-resistant
• Patients who had undergone subtotal colectomy or total colectomy
• Patients who had stoma

Adults patinets of moderately to severely active ulcerative colitis who will initiate IFX or CS