Objective: Studied Semi-automated synthesis methods to link radionuclide 18F to Cyclic arginine-glycine-aspartat (RGD) peptide E[c(RGDyK)]2, and explored bio-distribution after the tumor-bearing mouse were injected.Methods: After the N-succinimidyl 4-[18F]fluorobenzoate (18F-SFB) was automatically synthesized by multi-function module-assisted, The 18F-SFB was redissolved in anhydrous acetonitrile (MeCN).Cyclic RGD peptide E[c(RGDyK)]2 was mixed in anhydrous dimethyl suffixed (DMSO) and N,N-diisopropyl ethylamine (DIPEA) after most of the 18F-SFB had reacted.The final purification was accomplished by High Performance Liquid Chromatography (HPLC) gradient separation system and solid-phase extraction method.The N-4-[18F] fluorobenzoyl-RGD2 (18F-FB-RGD2) in vivo bio-distribution and competition test were studied by tumor-beating mouse.C57BL/6N mice were planted with Lewis lung cancer cells as the tumor-bearing mouse for testing.The tumor-bearing mouse was injected intravenously (i.v.) with approximately 1850 kBq (10μCi) of 18F-FB-RGD2 each.Animals were euthanized at 30 min, 60min, 90min and 120min post-injection (p.i.).Blood, heart, liver, spleen, lung, kidney, brain, small intestine, muscle and tumor were collected, wet-weighed, and counted in a γ-counter.The percent injected dose per-gram (%ID/g) was determined for each sample.The blocking experiments had been done with the tumor-bearing mouse post-inject the monomer RGD peptides an hour ago.Results: The labeled yield of 18F-FB-RGD2 was about 25.2±2.5%.It took about 115min from 18F ions to the 18F-FB-RGD2.The radiochemical purity was more than 95%.The tumor uptaking of 18F-FB-RGD2 were 6.13±0.12, 4.71±0.10, 4.51±0.18, 3.79±0.12%ID/g after injection of 30min,60mi, 90min, 120min respectively.The ratio of tumor to muscle was between 5.93 and 6.32.1 8F-FB-RGD2 had higher tumor uptaking, prolonging tumor uptaking times and decreasing uptaking in small intestine and liver.However, 18F-FB-RGD2 had higher uptaking in kidney.The tumor uptake was decreased dramatically after the tumor-bearing mouse blocked.Conclusions: 18F-FB-RGD2 was a promising imaging agent for tumor.The imaging agent can be automatically synthesized by the fully Semi-automated synthesis module.