An objective of the invention is to provide a hair dye composition having sufficient decolorizing performance and dying performance without exhibiting any irritative odor, and also having an ability of imparting the hairs with an excellent smoothness.The aspect of the invention is a hair dye composition comprising: a first agent containing an alkanolamine and an oxidation dye; and, a second agent containing an oxidant, wherein a higher alcohol and a quaternary ammonium salt cationic surfactant are contained in the first agent and/or the second agent; wherein the molar ratio of the higher alcohol to the quaternary ammonium salt cationic surfactant is in the range of 3 to 15. In the composition described above, it is preferable that substantially no ammonia is contained.