Layered-perovskite Pr1+x Ba1-x Co2O5+δ (PBC, x =0–0.30) oxides are designed and evaluated as cathode materials for solid-oxide fuel cells (SOFCs). The effect of x on structural, thermal and electrochemical properties has been systematically investigated. Analysis of X-ray photoelectron spectroscopy indicates the existence of mixed valences of Pr3+/Pr4+ and Co3+/Co4+. Among the series samples, the x =0.10 shows the best electrochemical performance. The conductivity reaches as high as 600 S cm–1 at 600–800°C. As cathode materials for electrolyte-supported single cells, the maximum power densities at 800°C are 408, 713, 732, 546 and 435 mW cm–2 for x =0, 0.05, 0.10, 0.20 and 0.30, respectively. Our results demonstrate that the layered-perovskite Pr1+x Ba1-x Co2O5+δ are potential cathode materials for SOFCs, which electrochemical properties can be improved by optimizing Pr/Ba molar ratio.