Interleukin-18（IL-18） is a pleiotropic and pro-inflammatory cytokine.It is one of the major cytokines that affect Th1/Th2 immune response imbalance,which plays an active role in immunoregulation.Inflammatory bowel disease（IBD） is a chronic inflammation of intestinal,which is characterized by abnormal immune reaction.Progress in the researches of IL-18 and its relationship with IBD was reviewed in the paper.