A composite cathode material for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC) was prepared by adding Ce0.8Sm0.2O1.9 into La0.7Sr0.3Co0.95Cu0.05O3-δ at different ratios. The crystal structure was characterized; the high temperature conductivity, thermal expansion coefficient and overpotentials of cathode electrodes were tested. The results show that adding Ce0.8Sm0.2O1.9 effectively decreases the thermal expansion coefficient of La0.7Sr0.3Co0.95Cu0.05O3-δ. When the content of the adding of Ce0.8Sm0.2O1.9 is 10% (mass faction, similarly hereinafter), the conductivity of the composite material is higher than that of La0.7Sr0.3Co0.95Cu0.05O3-δ and the current density of the cathode under the same overpotential is greater than that of others. A single fuel cell containing this cathode material has the maximum short-circuit current density of 511 mA/cm-2 and the maximum output power density of 106 mW /cm-2 at 850 °C.