PROBLEM TO BE SOLVED: To provide a hair-treating agent which exhibits a sufficient fade-preventing effect even to hair seriously damaged by chemical treatments, and can give a good touch to hair.SOLUTION: The hair-treating agent is characterized by comprising a component (A): one or more highly polymerized silicones selected from highly polymerized dimethylpolysiloxane, highly polymerized dimethiconol, and highly polymerized amino-modified silicone, each having an average polymerization degree in a specific range, a component (B): one or more ultraviolet ray absorbents, and a component (C): one or more acidic amino acids.COPYRIGHT: (C)2011,JPO&INPIT【課題】 化学処理による重度の損傷を受けた毛髪に対しても十分な退色防止効果を発揮し、かつ毛髪に良好な感触を与えることができる毛髪処理剤を提供する。【解決手段】 (A)成分:平均重合度が特定の範囲内にある高重合ジメチルポリシロキサン、高重合ジメチコノール及び高重合アミノ変性シリコーンから選ばれる高重合シリコーンの1種以上と、(B)成分:紫外線吸収剤の1種以上と、(C)成分:酸性アミノ酸類の1種以上を含有する毛髪処理剤。【選択図】なし