A preparation method of a latex polymer that includes a wax and a colorant, includes: preparing a dispersion containing a colorant and a wax; preparing an aqueous phase containing the dispersion; preparing an organic phase containing a monomer; mixing the aqueous phase with the organic phase, and preparing a mixture; homogenizing the mixture; and adding a polymerization initiator to the mixture, and causing polymerization. Embodiments of the present invention enable preparation of a latex polymer that includes the wax and the colorant through a single process, without utilizing any aggregation therefor. Also, the aggregation between the wax, the colorant and the latex particle is optimized, and the latex has an optimized particle size distribution.