To provide an oxidation hair dye composition having excellent hair dyeing power and affording a natural hair dyed state.

The oxidation hair dye composition is used by mixing with an oxidizing agent composition, comprises the following ingredients (a), (b) and (c) and satisfies the following conditions (1) and (2). the ingredient (a): 0.01-0.18 mol of N,N-bis(β-hydroxyethyl)-p-phenylenediamine or its salt in 1 kg of the oxidation hair dye composition, the ingredient (b): 0.06-0.46 mol of ascorbic acids in 1 kg of the oxidation hair dye composition and the ingredient (c): 0.08-0.90 mol of at least one kind of ingredient selected from a 28% ammonia water and monoethanolamine as an alkaline agent in 1 kg of the oxidation hair dye composition. the condition (1):1.3-2.7 molar ratio of the ingredient (b)/ingredient (a) and the condition (2): 0.6-8.7 molar ratio of the ingredient (c)/ingredient (b).