Zirconia nanoparticles were widely used as filler in order to get high refractive index layer. However, dispersion of nanoparticles is difficult due to their agglomeration in solvent. In this study, the dispersibility of the zirconia suspension is promoted by controlling the steric hindrance and electrostatic interactions through the adsorption of PEI according to alkali treatment time. Also, to induce improved dispersibility on suspension, we changed the dispersion conditions variously and fabricated an ink formulation method for the coating layer. Zirconia suspension was characterized by dynamic light scattering (DLS), Zeta potential measurement, Transmission Electron Microscope (TEM) and FT-IR. We were able to confirm that good dispersion of zirconia suspension by alkali treatment and PEI led to high refractive index.