Two polymeric dyes containing the anthraquinone structure were prepared via solution polycondensation. Their monomers were prepared through reactions between 1,5-dichloroanthraquinone and nucleophiles. The polymeric dyes were characterized with NMR and thermogravimetry. Their ultraviolet spectra, intrinsic viscosity, and solubility were also measured. Then, the polymeric dyes were applied to the mass coloration of poly(ethylene terephthalate) with good compatibility.