La(Sr)MnO3 cathodes have been investigated as high temperature oxygen reduction electrodes in the solid oxide fuel cells (SOFCs). The cathodes consist of 10 mole percent of yttria stabilized zirconia (YSZ) thin film electrolyte layer deposited on a porous La0.81Sr0.09MnO3 tube using the electrochemical vapor deposition method. The La(Sr)KnO3/YSZ cathodes have different electrochemical properties from those fabricated with the sintering method. The cathode polarization was about 1 mV at a current density of 1.5 A/cm2 in oxygen at 1000-degrees-C. This type of cathode has an extremely large phase boundary and large interfacial capacitance (more than 1 F/cm2) which is approximately proportional to the oxygen partial pressure.