Sm0.5-xGdxSr0.5CoO3-delta (SGSC, x=0, 0.1, 0.2, 0.3, 0.4, 0.5) powders were synthesized by a solution-combustion method. SGSC formed the major perovskite phase with an orthorhombic symmetry after calcined at 1200 degrees C. The electrical measurements indicated that the Gd3+content have a strong influence on the electrical conductivities of SGSC. It was found that the electrical conductivities of SGSC was firstly increased then decreased as the Gd3+ content changed from 0 to 0.5. The highest electrical conductivity with a value 1820 S/cm was obtained when the amount of Gd reached to 0.2.