By means of a facilely designed strategy, we successfully fabricated the multilayer and conductive organo-silica/polystyrene/polyaniline (organo-silica/PS/PANi) composite particles. First, organo-silica/PS core/shell composite particles were synthesized by seeded emulsion polymerization and the vinyl groups located on the surface of organo-silica nanoparticles were used to induce in situ polymerization of styrene. The influence of the route of the addition of styrene on the morphology of organo-silica/PS composite particles was investigated. Then, the coating of organo-silica/PS composite particles with PANi was achieved by virtue of the "Swelling-Diffusion-Interfacial-Polymerization Method" (SDIPM). The whole preparation process was monitored by transmission electron microscope, scanning electron microscope, Fourier transform infrared, Raman spectroscopy, dynamic light scattering, and thermogravimetry. As a result, the multilayer and conductive organo-silica/PS/PANi nanocomposites possessed of a uniform size and well-defined morphology, and furthermore, their structure could be well controlled by simply changing the weight ratio of aniline/PS. (C) 2010 Elsevier Inc. All rights reserved.