A new process for the dispersion of graphite in the form of nanosheets in a polymer matrix was developed via in situ polymerization of monomer at the presence of sonicated expanded graphite during sonication. Graphite nanosheets prepared via powdering the expanded graphite had a thickness ranging 30-80 nm and a diameter ranging 0.5-20 mum and was an excellent nanotiller for the fabrication of polymer/graphite conducting nanocomposite. The process fabricated electrically conducting polystyrene/graphite nanosheet nanocomposite films with much lower percolation threshold and much higher conductivities than those of composites made by conventional methods, (C) 2003 Elsevier Science Ltd. All rights reserved.