This paper reports a simple method for the controllable synthesis of highly effective SiO 2@Pt supported catalysts. Hybrid photoreactive silica nanoparticles (NPs) modified with benzophenone (SiO 2@BPh) were used as the supporting phase while Pt NPs were used as the catalyst. Monodisperse Pt NPs were homogeneously deposited on the supporting phase with full control of metal loading (from 2.15 to 34.60 wt%) via direct photoreduction of the PtCl 6 2- metal precursor. The catalytic activities of our supported catalysts were evaluated by the reduction reaction of 4-nitrophenol by sodium borohydride. These catalytic activities were found to be much higher than those of unsupported Pt NPs reported in the literature and commercial Pt/C supported catalyst. The facile synthetic method established in this study should largely contribute to the further development of various highly effective supported catalysts.