Strontium titanate with perovskite structure is one of potential candidates for alternative anodes for solid oxide fuel cells. Co-doped Y 0.08Sr 0.92TiO 3 − δ was synthesized via solid-state reaction. The effect of Co-doping on the electrical behavior of Y 0.08Sr 0.92TiO 3 − δ was investigated and a doping mechanism was proposed. Compared with Y 0.08Sr 0.92TiO 3 − δ , the electrical conductivities of Y 0.08Sr 0.92Co x Ti 1 − x O 3 − δ decrease obviously with increasing Co-doping amount at 25–1000 °C, while the ionic conductivities increase significantly at 500–1000 °C. The addition of Co can increase the oxygen vacancy concentration and enlarge the saddle point critical radius r c, both of them should be responsible for the remarkably enhanced ionic conductivity of Y 0.08Sr 0.92Co x Ti 1 − x O 3 − δ . The decreased electronic conductivity of Y 0.08Sr 0.92Co x Ti 1 − x O 3 − δ is ascribed to the lowered Ti 3+concentration, caused by the substitution of Co 3+. Co-doping increases the oxygen absorption temperature, and thus widens the operation temperature range of doped-SrTiO 3.