The enzyme, dipeptidyl peptidase Ⅳ(DPP Ⅳ), is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase Ⅳ inhibition improves the impaired insulin secretion and decrease postprandial concentrations of glucagon by enhancing the incretin hormone levels lucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide(GIP). Recently, DPP Ⅳ inhibitors have attracted more and more attention, several of which have entered pre-clinical and clinical trials, and one has received approval for use as an anti-diabetic agent. Among the DPP Ⅳ inhibitors, two leading agents(sitagliptin and vildagliptin) have been shown to be effective in reducing glycosylated hemoglobin(HbA1c) and fasting plasma glucose(FPG) in patients with type 2 diabetes. This review summarizes the evidence supporting DPP IV inhibitors as potential antidiabetic agents.