Highly oriented polyaniline (PANI) fiber was prepared by a polymerization at higher temperature and growth in lower temperature. Poly(sodium styrenesulfonate)/polyaniline multilayer film (PSS/PANI)(n) was layer-by-layer molecular-level self-assembled by a simple technique. The morphology and structure of the oriented PANI fiber were characterized, showing an emeraldine state and ordered molecular structure. The growth process and surface topography of the (PSS/PANI)(n) inultilayer film were characterized by UV-vis spectroscopy and atomic force microscopy. Absorbance plotted against the bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer film. The (PSS/PANI)(n) multilayer film exhibited an electrical conductivity in the order of 1 S cm(-1), and when bilayer number exceeded a threshold value of 4, the conductivity of the multilayer film increased dramatically. The electrochemical properties were studied through cyclic voltammograms, and it was found that the electrochemical activity of the (PSS/PANI)(n) film increased with the increase of the bilayer number. (C) 2009 Elsevier Inc. All rights reserved.