Ulcerative colitis (UC) and Crohn's disease (CD), the primary constituents of inflammatory bowel disease (IBD), are precipitated by a complex interaction of environmental, genetic, and immunoregulatory factors. A growing body of data implicates a dysfunctional mucosal immune response to commensal bacteria in the pathogenesis of IBD, especially CD. Medical management of IBD includes two treatment strategies: induction and maintenance of remission. 5-Aminosalycilates are mostly used for mild active IBD and for maintenance treatment of UC. Glucocorticoids remain, despite their frequent (and occasionally severe) side effects, as the mainstay for induction of remission in moderate to severe active IBD, both UC and CD. However, these agents, although beneficial for many patients with IBD, are not effective for the majority of patients over the long term. Immunomodulators including azathioprine(AZA), 6-mercaptopurine(6-MP), or methotrexate are effective in the treatment of CD or UC. Cyclosporine and infliximab have emerged as the main, rapid-acting, alternatives in steroid-refractory UC and CD, respectively. In addition, infliximb was approved recently in the treatment of UC. The large number of new agents presents a bewildering challenge to practitioners anticipating their use in the clinic. Unfortunately, in spite of recent remarkable advances in medical therapy of IBD, there have been no any curative therapeutic agents for IBD up to now. Therefore, the treatment is should be individualized according to the severity of the disease and clinical course of the patients with IBD. And, it is also very important to prescribe the therapeutic agents correctly and appropriately for the patients with IBD.