Poly(methyl methacrylate)/silica nanocomposites membranes were prepared by simple solution mixing method using three different solvents (acetone, acetonitrile and chloroform). The structure and thermal properties of these nanocomposites were investigated by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and environmental scanning electron microscope (ESEM). The infrared spectra confirm that the strongest H-bond interaction between the PMMA and silica was found when using chloroform solvent. In the case of thermal properties, the DSC and TGA analyses show significant improvement in thermal stability and glass transition temperature (Tg). Furthermore, the ESEM micrographs prove the structure stability of these synthesized nanocomposites. The results demonstrate that the solvent that lead to form the strongest H-bond interaction between the PMMA carbonyl groups and silica silanol groups (as chloroform solvent) will be more efficient in the synthesis of PMMA/SiO2 nanocomposites.