The effect has been investigated of the contents of Ru0.3Ti0.7O2 in a conducting polymeric composite material on the resistivity of this material and on the polarization resistance of the oxygen evolution reaction. A significant decrease in the resistivity of the composite material has been stated. Ru0.3Ti0.7O2 has an effect on the oxygen evolution reaction rate on investigated composite electrodes. A relation has been determined between the polarization resistance of the oxygen evolution reaction and the Ru0.3Ti0.7O2 content in the composite material. (C) 2001 The Electrochemical Society. All rights reserved.