Poly( methyl methacrylate) / silica( PMMA / Si O2) composites were synthesized by a simple technique of a monomer casting method and bulk polymerization. Nanosilica modified with silane coupling agent,methacryloxypropyltrimethoxysilane( γ-MPS),was characterized by Fourier transform infrared spectroscopy. Effects of modified silica particle content on thermal conductivity of PMMA / Si O2 composites were investigated. With 11. 76% of silica particles,the thermal conductivity of the composite is 0. 23 W /( m·K...