PROBLEM TO BE SOLVED: To provide an oxidation hairdye composition capable of preventing the hair damage and having excellent levelness.SOLUTION: This oxidation hairdye composition is characterized in that the composition contains an oxidation dye, an alkali agent and an oxidation agent, and has pH 7.5-8.9, and 0.3-0.8 mL/g alkalinity defined by the amount of consumption of 0.1 N acid standard solution.COPYRIGHT: (C)2002,JPO【課題】 毛髪損傷を防止し、均染性に優れる酸化染毛剤組成物を提供する。【解決手段】 酸化染料、アルカリ剤及び酸化剤を含有し、pH7.5~8.9、0.1N酸標準液の消費量で規定されるアルカリ度が0.3~0.8ml/gであることを特徴とする酸化染毛剤組成物。