A sensitive electrically conducting film was prepared by filling carbon blacks into a poly(vinylidene fluoride) matrix and then the film surface was modified by a plasma glow discharge technique. The relationship between the surface performance, microstructure and vapor response behavior of the conductive thin films was elucidated by an environmental scanning electron microscopy, a Fourier transform infrared spectrophotometer combined with the results acquired from the plasma treatment. The experimental results indicated that the vapor-induced response sensitivity, reproducibility and rate of the film to some solvent vapors could be improved by O-2 plasma treatment. Compared with the control sample, the response intensity of the O-2 plasma-treated thin films at 60 W reached 10(3) times to acetone vapor. The results from the surface structure analyses showed that the changes in the surface microstructure profiles and composition, including cross-linking, degradation, etching and functionalization derived from plasma treatment, played a favorable part in the surface performances and the response behavior. (c) 2006 Elsevier B.V. All rights reserved.