A polyaniline (PANT) film was successfully prepared on multiwall carbon nanotubes (CNTs) by modifying the CNTs with aromatic amine group (CNTs-(NC6H6)(n)) followed by aniline polymerization. TOF-SIMS was used to monitor C6H6N-, C2H3Cl-, C8H- and C-10(-) to reveal the interfacial change at PANT film/CNTs-(NC6H6)(n). The functionalized group of CNTs modified with aniline was determined to be C6H6N-, which showed positive effect on polymerization of aniline as shown by the TOF-SIMS ion image. (C) 2004 Elsevier B.V. All rights reserved.