Stable and smooth surface poly(glycidyl metharylate-co-divinylbenzene) (GMA-co-DVB) microspheres composed of various concentrations of DVB from 20 to 90 mol% in acetonitrile medium were prepared without a significant coagulum by precipitation polymerization. The numberaverage diameter of the microspheres linearly increases from 2.63 to 3.34 mu m and the particle size distribution becomes narrower by decreasing the uniformity from 1.10 to 1.02 with the DVB concentration from 20 to 90 mol%. The yield of polymerization increased from 28.9 to 79.7% with the DVB concentration as well. The FT-IR spectrum shows the characteristic peaks at 1725-1650 cm(-1) assigned to the confirmation of the polymerization between GMA and DVB. No glass transition temperature and the onset of the thermal degradation temperature at higher temperature indicate that the poly (GMA-co- DVB) is crosslinked; this is evidenced by the swelling ratio measurement relevant to the crosslinking density of the poly (GMA-co-DVB). The swelling test suggested that the poly(GMA-co-DVB) particles would be a core/shell type structure composing of a highly crosslinked DVB rich-phase in the core part and slightly crosslinked GMA rich-phase in the shell part. (c) 2007 Elsevier Ltd. All rights reserved.