Multi-layered adsorption of 3Y-ZrO2 nanoparticles on polystyrene (PS) microsphere using layer-by-layer (LBL) assembly technique was investigated. By employing sodium poly (acrylic acid) (PAANa) and polyethylenimine (PEI) to modify the zeta potential of the powders, the heterocoagulation takes place between the coating powders and microspheres substrate and the zirconia coating on the surface of polystyrene spheres was successfully formed. Dense, uniform multi-layered zirconia can be obtained on the surface of polystyrene spheres and the thickness of zirconia coating increased by repeating the coating process. The diameter of the spheres expands to 1.5 mu m after the first coating and 1.65 mu m after the third coating comparing with the original polystyrene spheres with diameter of 1.4 mu m. (C) 2006 Elsevier Ltd. All rights reserved.