This communication demonstrates the success in the anodic deposition of hydrous ruthenium oxide (denoted as RuO2 center dot xH(2)O) from RuCl3.xH(2)O in aqueous media with/without adding acetate ions (CH3COO-, AcO-) as the complex agent. The benefits of as-deposited RuO2 center dot xH(2)O include the low electron-hopping resistance and the low contact resistance at the Ti-Ru02-xH20 interface which are clarified in electrochemical impedance spectroscopic (EIS) studies. The cycling stability, specific capacitance, and power performance of as-deposited RuO2 center dot xH(2)O are further improved by annealing in air at 150 degrees C for 2h. The morphologies of as-deposited and annealed RuO2 center dot xH(2)O films, examined by scanning electron microscopy (SEM), are very similar to that of thermally decomposed RuO2. The high onset frequencies of 660 and 1650 Hz obtained from EIS spectra for the as-deposited and annealed RuO(2 center dot)xH(2)O films, respectively, definitely illustrate the high-power merits of both oxide films prepared by means of the anodic deposition without considering the advantages of its simplicity, one-step, reliability, low cost, and versatility for electrode preparation. (c) 2006 Elsevier B.V. All rights reserved.