Abstract: RGD peptides exist in extracelular matrix of many kinds of organisms,and they can specificly recognise and combin with integrin receptors. After combining with integrin receptors, extrinsic RGD peptides can prevent tumor cells them adhering and migrating, suppress agiogenesis and induce trunor cells apoptosis. And the derivates of RGD peptides can be used as specific imaging libelling and targetal drug dilivery system for tumor therapy.