Gd0.8Sr0.2CoO3-delta-XSm0.1Ce0.9O1.95 (GSC-x, x=0-50 wt.%) composite cathodes were prepared by Glycine-Nitrate Process followed by mixing GSC and SDC powder. The thermal stability and electrical conductivity of GSC-x composite cathodes have been investigated for the application in intermediate temperature solid oxide fuel cells (IT-SOFCs). The thermal expansion coefficient of GSC-x decreased with the addition of SDC. The electrical conductivities of GSC-x cathode with 0-30 wt.% SDC were passed the line of 100 S cm(-1). Especially for GSC-20, the conductivity of GSC-20 is more than 300 S cm(-1) in temperature range of 600-750 degrees C. The area specific resistance (ASR) of GSC-20 was only 0.080 Omega cm(2) at 750 degrees C, much lower than that of GSC cathode (ASR = 0.119 Omega cm(2)). The thermal expansion coefficient of GSC-20 decreased to 80% TEC of GSC cathode. (C) 2016 Elsevier Ltd. All rights reserved.