A dye concentrate for dyeing keratin fibers which comprises the following components (A), (B) and (C):(A) 10% by weight or more, based on the total weight of the composition, of an oxidation dye having two or more amino groups per molecule in the non-salt form or salt free;(B) 0.5% by weight or more, based on the total weight of the composition, of an inorganic or organic reducing agent; and(C) water or an organic solvent;and a dye composition for dyeing keratin fibers containing the same are disclosed. The dye concentrate of the present invention remains stable even when stored for a long time and can be easily formulated into a dye composition at use.