PROBLEM TO BE SOLVED: To provide a cleansing agent composition excellent in imparting good feeling on use and an effect of conditioning to hair and skin, having good low temperature stability, and favorable feeling on use when washing hair (foam forming, foam quality, and slippage) and favorable feels (smoothness, moistened feeling) when dried particularly to damaged hair.SOLUTION: The cleansing agent composition includes at least one member of anion surfactants (A), and an amphoteric surfactant (B) represented by general formula (1) (wherein R1CO is an isostearic acid residue R2 and R3 are each 1-3C alkyl or hydroxyalkyl R4 is 1-3C alkylene or hydroxyalkylene X is -COO or -SO3 and a is an integer of 1-5).COPYRIGHT: (C)2010,JPO&INPIT【課題】毛髪や皮膚に良好な使用感とコンディショニング効果の付与に優れ、かつ低温安定性が良好で、特にダメージヘアに対する洗髪時の使用感(泡立ち、泡質、滑り性)と乾燥時の感触(滑らかさ、しっとり感)が良好な洗浄剤組成物を提供すること。【解決手段】(A)アニオン界面活性剤の1種又は2種以上と、(B)下記一般式(1)(R1COはイソステアリン酸残基、R2、R3は炭素数1~3のアルキル基、ヒドロキシアルキル基、R4は炭素数1~3のアルキレンもしくはヒドロキシアルキレン、Xは-COOもしくは-SO3、aは1~5の整数を表す。)で表される両性界面活性剤を含有してなる洗浄剤組成物。【選択図】なし