The potential application of PrBaCo2O5+delta (PBC) double perovskite oxide as a cathode for a proton-conducting solid-oxide fuel cell based on a BaZr0.1Ce0.7Y0.2O3-delta (BZCY) electrolyte was systematically investigated. XRD and O-2-TPD results demonstrated that cation exchange between BZCY and PBC perovskites simultaneously occurs front the formation of Co3+-doped BZCY and Y3+-dopen PBC. This event does not significantly change the cathodic polarization resistance. Under real fuel Cell conditions, neither the electrolyte nor electrode resistances were significantly affected by the phase reaction and morphologic change of PBC. Anode-supported cells with ail electrolyte thickness of similar to 30 mu m were Successfully fabricated via a dual dry pressing process. Relatively high performance of 520 and 40 mW cm(-2) at 700 degrees C was achieved for the cell with it PBC cathode fired at 950 and 1100 degrees C, respectively. A low electrode polarization resistance of 0.06 Omega cm(2) was achieved at 700 degrees C for the PBC cathode calcined at 950 degrees C.