A multi -agent type hair treatment agent comprising a first composition containing component (A) and component (B) ； and a second composition containing component (C), wherein the weight ratio (H)/(C) of component (H) to component (C) in the second composition is less than 1. A hair treatment method comprising the steps of applying and rinsing the first composition to hair (i) and then applying the second composition to hair (ii).Component (A) : a carboxylic acid having an inorganic value of 230 or more and 450 or less and an organic value of 50 or more and 250 or less, or a salt of the carboxylic acidComponent (B): anionic surfactantComponent (C) : an aromatic sulfonic acid having amolecular weight of 300 or less or a salt thereofComponent (H): cationic surfactant
