Abstract: Integrin α_vβ₃ receptor is not only expressed on cells surface of many malignant tumors with higher level,but expressed on the neovasculature endothelial cell membrane in malignant tumor tissue with extremely high density and has no expression or cannot be detected in mature vascular endothelial cell and most of the normal organic system.The small molecul cyclic peptides containing RGD motif is an effective antagonist for α_vβ₃ receptor,which have height selectivity and affinity bind to α_vβ₃ receptor and is one kind of potential tumor receptor imaging agnet.