A saccharide residue-functional organopolycarbosiloxane containing at least two monosaccharide or polysaccharide groups per molecule in which a specific site on the monosaccharide or polysaccharide is bonded to silicon through a thioether bond. Also, a method of preparing the saccharide residue-functional organopolycarbosiloxane, comprising condensing a saccharide residue-functional metal thiolate compound wherein the metal is an alkali metal atom or alkaline-earth metal atom, and an organopolycarbosiloxane containing groups having the formula --R.sup.2Q wherein R.sup.2 is C.sub.2 to C.sub.10 alkylene, and Q is a group selected from halogen atoms, C.sub.1 to C.sub.10 alkylsulfonate groups, and C.sub.6 to C.sub.20 arylsulfonate groups.