Poly(styrene-co-divinylbenzene) microspheres with size ranging from 1.6 to 1.8 mu m were prepared in acetic acid by precipitation polymerization. The particle size and particle size distribution were determined by laser diffraction particle size analyzer, and the morphology of the particles was observed with scanning electron microscope. Besides, effects of various polymerization parameters such as initiator and total monomer concentration, divinylbenzene (DVB) content, polymerization time and polymerization temperature on the morphology and particle size were investigated in this article. In addition, the yield of microspheres increased with the increasing total monomer concentration, initiator loading, DVB concentration and polymerization time. In addition, the optimum polymerization conditions for synthesis of monodisperse crosslinked poly(styrene-co-divinylbenzene) microspheres by precipitation polymerization in acetic acid were obtained. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012