Functionalized graphene oxide (FGO) was prepared by treating graphene oxide with γ-aminopropyl triethoxysilane (KH-550) before the mixture was dispersed into α, ω-dihydroxy polydimethylsiloxane to get room temperature vulcanized (RTV) silicone rubber composites by solution casting. The cured composites were then reduced with hydrazine hydrate to obtain functionalized graphene (FG)/RTV silicone rubber composites. The structures of FGO and the resultant composites were characterized by atomic force microscopy, FT-IR spectra and X-ray diffraction. KH-550 was found to be grafted onto graphene sheets, leading to an increased interlayer spacing. Significant improvements in thermal and mechanical properties were obtained. Both the FGO/RTV silicone rubber composite contain 1.0 wt% of FGO, and its reduced product showed an increase of one-step weight loss temperature with 61 ℃ and 133 ℃ higher than that of pure silicone rubber. Tensile strength and elongation at break of FG/RTV silicone rubber composite (with 0.5 wt% FGO content) increased by 175% and 67%, respectively, compared with those of pure silicone rubber. Functionalized graphene oxide (FGO) was prepared by treating graphene oxide with γ-aminopropyl triethoxysilane (KH-550) before the mixture was dispersed into α, ω-dihydroxy polydimethylsiloxane to get room temperature vulcanized (RTV) silicone rubber composites by solution casting. cured composites were then reduced with hydrazine hydrate to obtain functionalized graphene (FG) / RTV silicone rubber composites. The structures of FGO and the resultant composites were characterized by atomic force microscopy, FT-IR spectra and X-ray diffraction. KH-550 was Found to be grafted onto graphene sheets, leading to an increased interlayer spacing. leading to an increased interlayer spacing. Significant improvements in thermal and mechanical properties were obtained. Both the FGO / RTV silicone rubber composite contain 1.0 wt% of FGO, and its reduced product showed an increase of one- step weight loss temperature with 61 ° C and 133 ° C higher than that of pure silicone rubber. Tensile strength and elongation at break of FG / RTV silicone rubber composite (with 0.5 wt% FGO content) increased by 175% and 67% respectively respectively, compared with those of pure silicone rubber.