In this study, a homogenization method is employed to determine the values of effective elastic modulus for BaZrO3 which is a promising candidate material for electrolyte in solid oxide fuel cell (SOFC). Comparison between the homogenization and the analysis data reveals that the difference becomes significant with increasing of porosity when upper 20%. The empire mechanic behavior in a typical planar fuel cell is evaluated using finite element method (FEM). Large stress gradient occurs in vicinity of the interface of the electrolyte and the cathode due to theirs mismatch of thermal expansion coefficient (TEC). Moreover, local processing results reveal that microscopic stress concentration around pore near the interface of the electrolyte and the cathode in the cell perhaps produces cracks which may lead to the fail of the electrolyte and the lower energy convention efficiency. © 2011 Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.