Proton conducting oxides based on the $BaCe_{0.9}M_{0.1}O_{3-{delta}}$ (M = La, AL) were tested for the alternative electrolyte materials of fuel cell. The power density for single cell of Air |Pt| $BaCe_{0.9}M_{0.1}O_{3-{delta}}$ |Pt| $H_2(3%H_2O)$ system was maximum $0.04W/cm^2$ at $1000^{circ}C$. In this system, proton transport number was proved to depend on the lattice parameters and the distortion of $CeO_6$ octahedral as a function of the ionic radii of acceptor ions. This proton conducting oxide system requires developing the new electrode materials for application.