The polyaniline of different intrinsic oxidation states, viz., the emeraldine (EM) and the leucoemeraldine (LM) states, were coated on 3-aminopropyltriethoxy silane modified fly ash cenospheres. Without prior sensitization by SnCl2 solution, Pd activation by PdCl2 solution was carried out on EM and LM laden cenospheres, followed by electroless plating of copper (Cu). The topography and composition of the composites were characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, etc. The results indicate that the oxidation state of the LM layer showed a much bigger increase than that of the EM layer in the Pd activation process, while coupled Pd reduction underwent to a more extent on the LM layer. The metallic Pd atoms on the LM and EM layers surface initiated the subsequent electroless plating of Cu, and the coated Cu on LM laden cenospheres had a much more uniform and compact morphology than that on EM laden cenospheres. Copyright © 2012 John Wiley & Sons, Ltd.