Protein tyrosine phosphatase 1B (PTP1B) is the first characterized PTP which was purified from human placental tissue as early as in 1988.Accumulating evidence demonstrates that PTP1B could dephosphorylate the insulin receptor (IR) or insulin receptor substrate (IRS) in skeletal muscle and liver,which involved in the control of IR signaling pathway,and these signaling events result in the homeostatic regulation of the blood glucose level.