Polymeric tributylstannyl eater of silicic acid (PTBS) was demonstrated to be a useful intermediary compound for the preparation of polysiloxane derivative (MPS), which possessed methacryloyloxypropyl groups. The reaction of PTBS and (3-methacryloyloxypropyl)dimethylchlorosilane (1a) proceeded readily at room temperature under neutral conditions to give MPS with the elimination of tributyltin group. The reaction conducted in the presence of 1a and trimethylchlorosilane (1b) was effective for the preparation of MPS containing the both silyl groups, in which the content of methacryloyloxy groups could be controlled. The obtained MPS polymerized readily under UV irradiation to afford the organic-inorganic hybrid resin (MSR) as a kind of organically modified silica gel.