PROBLEM TO BE SOLVED: To provide a hairdressing agent with high efficacy.SOLUTION: A hairdressing agent composition comprises components (A) and (B): (A) a copolymer of a monomer represented by formula (1) and a monomer represented by formula (2) [Rand Rare H or CH Ris a Calkyl group Ris a Calkyl group p is 20-90] and (B) poly(N-acyl alkylene imine) modified organopolysiloxane.SELECTED DRAWING: None