PURPOSE: To provide a new compound useful for introducing a functional group such as silanol or a reactive unsaturated group into various organic resins.

CONSTITUTION: The compound or formula I [R1 is H or 1-4C alkyl; R2 is a 1-4C monovalent hydrocarbon; (a) is 0-3; (b) is 1-3; (c) is 0-2; (b+c) is 2 or 3], e.g. bis(dimethylhydroxysiloxy)methylsilyl methacrylate. This compound of formula I is obtained by hydrolyzing an organosilicon compound of formula II [(d) is 2 or 31 having hydrogen bound to silicon atom (Si-H) with a transition metal compound (e.g. active carbon supporting Pd), etc., in a solvent (e.g. THF) at a temperature from ambient temperature to 100°C. The compound of formula II which is a raw material is readily obtained by cohydrolysis of a methacryloxyalkylalkoxysilane with dimethylhydrogenchlosilane.