Hydrous ruthenium oxide (RuO2 center dot nH(2)O) thin film electrodes were fabricated by cathodic electrodeposition on titanium substrates. The surface morphological characteristics of the RuO2 center dot nH(2)O films were examined by scanning electron microscopy, and their images show the uniform spherical grains with nanometer sizes and porous network structure of the RuO2 center dot nH(2)O films on Ti substrate. The electrochemical performances of the composite for supercapacitors were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and charge/discharge technique. The RuO2 center dot nH(2)O films exhibit good capacitive behavior, such as high reversible characteristics, excellent cycle stability, and superior power characteristics. The maximum specific capacitance of the RuO2 center dot nH(2)O film electrode is 786 F g(-1) achieved with deposit mass of 0.17 mg. (c) 2008 Elsevier B.V. All rights reserved.