Yttrium doped strontium titanate with A-site deficiency ((Y0.08Sr0.92)(1-x)TiO3-delta) was synthesized by conventional solid state reaction. The deficiency limit of A-site in (Y0.08Sr0.92)(1-x)TiO3-delta is below 6 mol% in Ar/H-2 (5%)at 1500 degrees C. The sinterability of (Y0.08Sr0.92)(1-x)TiO3-delta samples decreases slightly with increasing A-site deficiency level (x). The ionic conductivity of (Y0.08Sr0.92)(1-x)TiO3-delta samples increases while the electronic conductivity decreases with increasing A-site deficient amount The defect chemistry analysis indicates that the introduction of A-site deficiency results in not only the increase of oxygen vacancy concentration but also the decrease of Ti3+-ion concentration. The latter plays the main role in the electrical conduction. (Y0.08Sr0.92)(1-x)TiO(3-delta)shows good thermal-cyclic performance in electrical conductivity and has an excellent chemical compatibility with YSZ electrolyte below 1500 degrees C (C) 2008 Elsevier B.V. All rights reserved.