A series of polysiloxane-bound platinum complexes was prepared by the reaction of chloroplatinic acid with silica-supported polysiloxane ligands containing Sand -COOH (D) groups. These were tested as catalysts for the hydrosilylation of acetylene and olefins with functional groups, with the aim of synthesizing organosilicon monomers and silane coupling agents. It was found that supported platinum Catalyst A was an active catalyst for the hydrosilylation of acetylene and allyl chloride by dichloromethylsilane or trichlorosilane. By these catalytic reactions, several useful organosilicon monomers, such as dichloromethylvinylsilane and 3-chloropropyl-trichlorosilane, were obtained in good yield. Supported platinum Catalysts B, C, and D proved to be effective for the hydrosilylation of allyl glycidyl ether by trimethoxysilane to yield an important silane coupling agent, 3-glycidoxypropyltrimethoxysilane. The stability of supported Catalyst A is reported.