A facile synthetic approach for the design of peripherally post-functionalized multiarm star block copolymer has been established by nucleophilic aromatic substitution reaction of pentafluorophenyl periphery functional multiarm star polymer with alcohol moieties of poly(ethylene glycol) (PEG-OH) under mild reaction conditions. For this purpose, alpha-fluoro-functionalized PS (alpha-fluoro-PS) was prepared by atom transfer radical polymerization (ATRP) of styrene (St) and was allowed to react with divinyl benzene (DVB) as a linking agent yielding (fluoro-PS)(n)-polyDVB multiarm star polymer. Then, (PEG)(m)-(PS)(n)-polyDVB multiarm star block copolymer was synthesized via nucleophilic addition of PEG-OH precursor with (fluoro-PS)(n)-polyDVB multiarm star polymer in the presence of sodium hydride in tetrahydrofuran at reflux for 3 h. Multiarm star polymers were characterized using triple detection gel permeation chromatography (TD-GPC), FT-IR, H-1 NMR, F-19 NMR and C-13 NMR.