Abstract: Functionalized graphene oxide (named GO-Si) was synthesized with graphene oxide and triethoxyvinylsilane (TEVS) in tetrahydrofuran solution by γ-ray irradiation. TEVS was found to be grafted successfully onto GO sheets and the polysilane content on the GO-Si was increased with the increasing absorbed dose. The structures of GO-Si were testified by Fourier Transform Infrared Spectroscopy and Raman Spectra. The resultant GO-Si was dispersed into α, ω-dihydroxypolydimethylsiloxane to prepare room temperature vulcanized silicone rubber composites (named SR/GO-Si) by solution casting. The dispersion of GO-Si was more uniform than that of GO. Compared to the pure SR, thermal conductivity of SR/GO-Si-1.95 composites was increased from 0.13 W•m^-1•K^-1 to 1.1 W•m^-1•K^-1, and its tensile strength increased 149%. Moreover, the Shore A hardness and the tensile strength of SR/GO-Si were both improved after being radiated by γ-ray with absorbed dose 90 kGy. The results proved that the SR/GO-Si with high thermal conductive ability in this study is promising application as the thermal interfacial functional material in low dose radiation enviroment.