Abstract: The conductivity of several perovskite-type and similar perovskite-type oxide materials was investigated. The experimental results showed that the conductivities of La_0.8Sr_0.2MnO₃, La_0.8Sr_0.2 Ni_0.1Mn_0.9O₃, La_0.8Sr_0.2 Ce_0.1Mn_0.9O₃ and SrFe_0.5Co_0.5O₃ are approximative and all arrive at 10^-1 S·cm^-1. LaLiMnO_y and LaLi_0.5MnO_y, whose stabilities in molten carbonate are excellent, are different in conductivity. The former is more than 1 S·cm^-1, which meets the need of cathode materials of MCFC, and the latter is only 10^-2 S·cm^-1. A much higher activation energy of 0.191 eV should be the reason that the conductivity of LaLi_0.5MnO_y is lower.