Hyperbranched polystyrenes (PS) were prepared by living radical photopolymerization of 4-vinylbenzyl N,N-diethyldithiocarbamate as an inimer under UV irradiation. These hyperbranched PS exhibited large amounts of photofunctional dithiocarbamate groups on their outside surfaces. Subsequently, we derived the star-hyperbranched copolymers by grafting from hyperbranched macroinitiator with t-butyl methacrylate. We obtained poly(methacrylic acid) star-hyperbranched PS nanospheres by hydrolysis of poly(t-butyl methacrylate) grafted chains. We studied in detail two-dimensional nanopattern formation on poly(4-vinylpyridine) (P4VP) or partially quaternized P4VP substrate using such nanospheres by electrostatic interaction. (C) 2004 Elsevier Inc. All rights reserved.