Abstract: Colored resin particles which are colored uniformly and densely and are excellent in fluorescence, light fastness and washing resistance are prepared by copolymerizing in an aqueous medium in the presence of a water-soluble fluorescent dye (1) a polymerizable unsaturated monomer A having a low affinity for the fluorescent dye, (2) a polymerizable unsaturated monomer B having at least one cyano group and (3) a polymerizable unsaturated monomer C having a high affinity for the fluorescent dye and being insoluble or barely soluble in water, which is represented by the following general formula ##STR1## wherein X is a hydrogen atom or a methyl group.