A method for preparing an electrophotographic printing-use developer by mixing components of toner material, fusing and kneading the toner material, and then crushing and classifying the toner material, includes the step of arranging carbon black which is one of the components of the toner material to contain water before the mixing step. This arrangement permits even dispersion of water in the mixture of the components, prevents the flowability of the mixture from being lowered, and achieves stable kneading. Therefore, improved dispersion of the components is achieved. Since water adsorption is stable, water-treated carbon showing reduced water segregation is obtained. Consequently, high quality less foggy images with high resolution are obtained.