A polymeric dye compound, photosensitive resin composition comprising the same and use thereof are disclosed. The polymeric dye compound comprises three kinds of monomeric units. The photosensitive resin composition comprises a colorant, an alkali-soluble resin, a polymerizable monomer and a polymerization initiator, wherein the colorant comprises the polymeric dye compound and a pigment. The polymeric dye compound is prepared by copolymerization of styrenic monomer and other monomers, such that a colored layer having excellent heat resistance, light resistance and high transmittance can be formed.