Ceria based materials are widely used as a cathodic interlayer of low-temperature solid oxide fuel cell (LT-SOFC, operating temperature <500℃) because of their high oxygen ion conductivity and oxygen surface exchange coefficient even at relatively low temperature. Since zirconia doped ceria has better catalytic properties than pure ceria, this study investigated the effect of the composition of ceria and zirconia composite on the performance of SOFC with zirconia doped ceria cathodic interlayer. Atomic layer deposition (ALD) was used to deposit zirconia doped ceria interlayer for conformal coating of the electrolyte surface with easy composition control. The ratio of zirconia was changed to 0, 30, 80, and 100%. The SOFC performance was measured by I-V curve and EIS measurement at 450℃. The maximum power density of the cell with the zirconia doped ceria interlayer was higher than those of the cells with zirconia-only or ceria-only interlayers. Also the maximum power density of the cell with the zirconia doped ceria interlayer increased by 60% compared to that of the reference cell without the interlayer. In addition, the activation resistance was also reduced by ~50% compared to the cell without interlayers