The synthesis of latex two-phased polystyrene blends has been accomplished by three different mixing routes : (1) PS-b-XPS system consisting of a physical blend of polystyrene (PS) and crosslinked polystyrene (XPS) lattices, the latter being lightly crosslinked with divinylbenzene (less than 1% DVB), (2) (XPS-s)-PS system obtained by styrene polymerization in presence of a XPS seed latex, and (3) (PS-s)-XPS system, in which styrene and DVB are copolymerized in presence of a PS seed latex. Structuring of these PS/XPS systems resulted in different microstructures by each of the procedures. Different rheological behaviors have been noticed, along with a rather interesting property dependence on XPS content and DVB concentration. The polymerization method appears to be critical to the development of well-characterized, tailor-made latex microstructures, insofar as the order of monomers addition determines much of the polymerization sites.