Polystyrene particles incorporating poly(methylphenylsilane) (PMPS) were synthesized by miniemulsion polymerization 'UV irradiation of the emulsion under air in the presence of metal salts such as HAuCl4 center dot 4H(2)O, AgNO3, and Na2PdCl4 led to the formation of metal nanoparticles on the surface of polymer particles; thus, metal nanoparticle/ polymer hybrid particles were obtained. The structures of the hybrid particles were confirmed by the surface plasmon resonance band and transmission electron microscopy images. The formation of metal nanoparticles depended on the functional groups and charge on the surface of the polymer particle. The metal nanoparticles were formed due to the reduction of metal ions, accompanied by the oxidation of PMPS. The interaction between the surface of the polymer particle and the metal ions plays an important role in the formation of the metal nanoparticle.