Nickel oxide and yttria stabilized zirconia (NiO/YSZ) cermets have been prepared using a chemical co-precipitation of hydroxides. The influence of different factors on the microstructure and electrochemical properties of the anode was investigated. The anodes were characterized by impedance spectroscopy at open-circuit potential and under current load at 850 degrees C in hydrogen/steam atmosphere (H-2:H2O=1:1). The anode polarization resistance was identified by deconvolution of impedance spectra and the influences of current load and pH(2)O on the impedance spectra of the anode were discussed. Long-term stability of the cell with an anode prepared by co-precipitation was carried out over 1000 h under current density of 430-450 mA/cm(2)@0.7 V at 850 degrees C. (C) 2008 Elsevier B.V. All rights reserved.