Followed the sequential strategy from C-terminal to N-terminal one by one, RGD with protected C-terminal and N-terminal are obtained by coupling reaction of Asp(OBzl)-OAllyl with Boc-Gly and Cbz-Arg(Cbz)₂ respectively using Asp, Gly, Arg as raw materials and HBTU as coupling reagents. Allyl of the RGD derivatives is removed in the presence of (PPh₃)₄Pd/N-methylmorpholine to get the target product. The intermediates and the target product are purified by recrystallization and column chromatography, and their structures are determined by ¹H NMR, ¹³CNMR and MS.