Polystyrene microspheres were prepared by dispersion polymerization of styrene in a mixture of ethanol and 2-methoxyethanol in the presence of surfactant, polyvinylpyrrolydone, at 73 ℃ under N2 and were coated with tetraethoxy silicate using ammonium hydroxide as a catalyst at room temperature. The effects of surfactants, the stirring rate and the polymerization time on the morphology, size and size distribution were inspected.