A detergent composition, which imparts smoothness in finger-combing in rinsing after washing and smoothness, silky texture and non-stiffness to hair after application and drying is provided. The detergent composition comprises a copolymer having no cross-linking units and comprising constituting units corresponding to a cationic vinyl monomer (A) and constituting units corresponding to a specific vinyl monomer (B) having a hydroxyl group or an amide group, wherein the proportion of the constituting units corresponding to the cationic vinyl monomer (A) is from 25 to 45 mol % based on the entire constituting units constituting the copolymer.
