The present invention relates to a cosmetic composition in the form of an O/W emulsion, and comprises: (a) at least one fatty alcohol； (b) at least one oil； (c) at least one nonionic surfactant having an HLB value of 15 or more； (d) at least one nonionic surfactant having an HLB value of 5 or less； (e) at least one diol having a straight chain of four or more consecutive carbon atoms； (f) at least one alkaline agent selected from the group consisting of ammonia, ammonium hydroxide, ammonium salts, and mixtures thereof； and (g) water. The composition according to the present invention is easy to handle and can provide keratin fibers such as hair with superior cosmetic effects such as good coloring or bleaching effects as well as a good feeling to the touch of the keratin fibers, while controlling malodor due to an ammonia ingredient in the composition.
