Polyaniline (PANI) has been successively synthesized in aqueous diethylene glycol solution medium by chemical oxidative polymerization of aniline using ammonium peroxidisulfate [(NH4)(2)S2O8] as an oxidant in an aqueous solution of 0.5M acetic acid (CH3COOH) as a dopant. Polyaniline-lead (PANI-Pb) and polyaniline-copper (PANI-Cu) nanocomposites have been chemically prepared for the first time by oxidative polymerization of aniline in aqueous diethylene glycol/acetic acidic medium. The synthesized PANI and nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR). Conductivity measurements of the polymer and nanocomposites were performed using the four-probe technique. Morphology changes of the composites were investigated by scanning electron microscopy (SEM). PANI nanotubes were formed without added codopant, but when Pb(CH3COO)(2) or Cu(CH3COO)(2) was added as a codopant, the morphology of PANI obviously changed. The PANI-Cu and PANI-Pb nanocomposites exhibit higher conductivity than the PANI homopolymer, but the conductivity of the composites slightly decreased on increasing the metal concentrations.