Polyacrylate/silica hybrids were prepared by emulsifier-free emulsion polymerization and the sol-gel process. The influence on the properties of polyacrylate/silica hybrids of the synthetic conditions, such as the dosage of polyvinyl alcohol, the ratio of the monomers, the dosage of tetraethoxysilane and the dosage of gamma-methacryloxypropyltrimethoxysilane, was investigated. The hybrid material was characterized by Fourier transform infrared, differential scanning calorimeter, thermal gravimetric analyzer and dynamic light scattering. The results indicated that there were chemical bonds between SiO2 and polyacrylate, that the thermal stability and the average diameter of polyacrylate emulsion particle increased with the incorporation of SiO2, and that the glass transition temperature (T (g)) of polyacrylate/SiO2 was 8 A degrees C higher compared with that of pure polyacrylate.