The ultrafine nickel particles/polyaniline nanocomposite materials were synthesized in situ polymerization by two step series W/O inverse microemulsion systems. As the first step, the ultrafine nickel nanoparticles whose diameter is 10～30 nm were prepared by the W/O inverse microemulsion systems and by the reduction. As the second step, the monomer aniline salt (AnH +Cl -)entered into the polar waterpools where contained nickel nanoparticles and the ultrafine nickel particles/Polyaniline nanocomposite materials whose diameter is 50～100 nm had been obtained by in situ polymerization. These nanocomposite materials were measured to characterize and the micromorphology, microstructure and physical interaction of the both ultrafine nickel particles and polyanilines were studied by transmission electron microscopy (TEM), XRD, infraed spectrum (IR).
