The synthesis of functional magnetic polymer latexes (MPLs) with epoxy groups introduced via a modified miniemulsion polymerization route was described. The epoxy group content on the surface could be controlled by seed emulsion followed and characterized by FTIR and zeta potential measurements. We also developed a novel approach to achieve manipulation of the morphology of the MPLs based on kinetic control of the polymerization system. MPLs with different morphologies were obtained ranging from core shell microstructures, dispersed microstructures to asymmetric microstructure, which were characterized by TEM, DLS, and TGA. The mechanisms of the contribution of kinetic factors such as polymerization rate, reaction time, and temperature contributing to the formation of the different morphologies were also investigated. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2284-2293, 2010