The present invention provides an oxidation hair dye which comprises a first agent containing an alkaline agent and a second agent containing an oxidizing agent, said first and second agents being to be mixed together, characterized by, immediately after mixing the first agent with the second agent, said oxidation hair dye containing a bicontinuous microemulsion phase or a lamellar liquid crystal phase. The purpose of the present invention is to acquire an oxidation hair dye, which can exert a good dyeing effect on both damaged hair (hair chemically damaged by the use of hair dyes, perming agents, etc. and hair mechanically damaged by friction, etc.) and non-damaged healthy hair, by using a base agent that contains a bicontinuous microemulsion phase or a lamellar liquid crystal phase.本發明提供一種氧化染毛劑，其係混合包含鹼劑之第一劑與包含氧化劑之第二劑而成者，其特徵在於：於剛混合上述第一劑與第二劑之後，含有雙連續微乳液(bicontinuous microemulsion)相或層狀(lamella)液晶相。本發明之目的在於：獲得一種藉由使基劑中含有雙連續微乳液相或層狀液晶相，而對受損之毛髮(受到染毛劑、燙髮劑等化學性損傷及摩擦等物理性損傷之毛髮)與未受損之健康毛髮的兩者之染色性均良好之氧化染毛劑。
