An electrochemical method for the preparation of polyanitine-silver (PANI-Ag) nanocomposite film was proposed in this communication. Unsymmetrical square wave current method (USCM), which is characterized by the combination of an anodic process of aniline monomer polymerization and a cathodic process of metal ionic electrodeposition, was used to produce the PANI-Ag nanocomposite film. The results show that the PANI-Ag nanocomposite film prepared by USCM has fibrous structure and the Ag nanoparticles not only dispersed on the surface of PANI film but also embedded in the PANI matrix. The cyclic voltammetry and electrochemical impedance spectroscopy results show that the PANI-Ag nanocomposite film exhibits considerably higher electroactivity compared with PANI film without Ag particles. The influences of synthesis parameters, such as the cathodic current density and total synthesis time, on the electrochemical property of PANI-Ag nanocomposite film were also investigated. (c) 2006 Elsevier B.V. All rights reserved.