Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalentlygrafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiatedgraft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified byATR–FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiationtime and initiator concentration on the grafting density was investigated. Comparing with thevirgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surfaceenergy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-proteinadsorption to the SEBS surface.