To obtain a hair dye composition simple to use, excellent in hair dyeing effects and fastness, scarcely damaging hair without using an oxidizing agent and without causing fouling of skin by making the composition include a direct dye and thioglycolic acid therein.

This composition is obtained by including (A) a direct dye (e.g. nitro-p-phenylenediamine) and (B) thioglycolic acid and/or its salt (e.g. ammonium thioglycolate). In the composition, 0.01-10 wt.% of the ingredient A and the ingredient B in an amount of 0.005-2 wt.% expressed in terms of the thioglycolic acid are preferably contained. Furthermore, (C) 0.1-25 wt.% of a solubilizer (e.g. polyethylene glycol), (D) ≥0.01 wt.% of a thickening agent comprising an anionic polymer such as gum arabic and (E) 0.01-5 wt.% of a cationic surfactant or a cationic polymer, as necessary, are preferably contained in the composition.