PURPOSE: To obtain a compound which comprises the main chain of a polysaccharide compound or a protein compound and the side chain of an organopolysiloxane and can be used as a skin cosmetic because of its high biodegradability, high safe guard for human bodies and good enviromental assimilation.

CONSTITUTION: This organopolysiloxane-containing polysaccharide compound or protein compound comprises a main chain composed of a polysaccharide compound or protein compound and a side chain composed of an organopolysiloxane. The organopolysiloxane is represented by the formula (A is a divalent group; B is a divalent aliphatic group; R1, R5 are each an aliphatic group, an aromatic group; (p) is 0, 1; (m) is 0, 1; (n) is an integer of 5 to 500). The organopolysiloxane-containing compounds are used in cosmetics as a coating film-forming agent.