Nano-TiO2 is modified by a method, by which nano-TiO2 first reacts with silane coupling agent WD-70 with double bond group which subsequently copolymerizes with methyl methacrylate and butyl acrylate to produce a thin polymer shell on the nanoparticles. The modified nanoparticles have stable organophilicity. They are applied to polyacrylate coating and performances of the coating are measured by different methods. The modification of nano-TiO2 particles can improve their dispersibility in coating, enhance hardness of coating and reduce water absorption and permeability of polyacrylate coating. The mechanism has been analyzed in this paper. (c) 2005 Elsevier B.V. All rights reserved.