PROBLEM TO BE SOLVED: To provide oxidative hair dye compositions, oxidative hair dye kits and oxidative hair dyeing methods for improving mixing properties while imparting desired viscosity by the combination of a hydrophobically modified alkyl cellulose which is a cellulose derivative and a surfactant.SOLUTION: Provided are an oxidative hair dye composition, an oxidative hair dye kit and an oxidative hair dyeing method, the oxidative hair dye composition containing (A) hydrophobized modified alkyl cellulose (HYDROXYPROPYL METHYLCELLULOSE STEAROXY ETHER) which is a cellulose derivative and (B) at least one surfactant.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2020,JPO&INPIT【課題】 セルロース誘導体である疎水化変性アルキルセルロース及び界面活性剤の組み合わせにより、所望の粘度を付与しながら混合性を向上する酸化染毛剤組成物、酸化染毛剤キット及び酸化染毛方法を提供すること。【解決手段】 酸化染毛剤組成物は、（Ａ）セルロース誘導体である疎水化変性アルキルセルロース（HYDROXYPROPYL METHYLCELLULOSE STEAROXY ETHER）と、（Ｂ）少なくとも１種の界面活性剤；を含有する、酸化染毛剤組成物、酸化染毛剤キット及び酸化染毛方法。【選択図】図３
