A cosmetic composition comprising a polysiloxane copolymer comprising a repeating unit (A) having at least one anionic group, a repeating unit (B) having at least one linear or branched alkyl group having 8 to 64 carbon atoms, and a polysiloxane repeating unit (D), said repeating units (A), (B), and (D) being bonded with one another via diisocyanate residue represented by the following formula (1) wherein X is a divalent hydrocarbon group selected from the group consisting of aromatic hydrocarbon groups, aliphatic hydrocarbon groups, and alicyclic hydrocarbon groups. Cosmetics comprising the composition maintains their effects for a prolonged period of time.