A series of SiO2/poly(styrene-co-butyl acrylate) nanocomposite microspheres with various morphologies (e.g., multicore-shell, normal core-shell, and raspberry-like) were synthesized via miniemulsion polymerization. The results showed that the morphology of the composite latex particles was strongly influenced by the presence or absence of the soft monomer (butyl acrylate), the particle sizes of the silica, and the emulsifier concentrations. The incorporation of the soft monomer helped in forming the multicore-shell structure. (c) 2006 Wiley Periodicals, Inc.