The effects of Co and Fe dopants with the amount of 20 and 40 mol% on the properties of La0.84Sr0.16MnO3 were investigated. All compositions were prepared by conventional mixed oxide process and sintered at 1450 jC. The structure of undoped and Co-doped compositions was found to be monoclinic. In addition, the second phase was observed in these sintered compositions. The conductivity of doped materials decreased as compared to that of La0.84Sr0.16MnO3. The SEM microstructure showed the decrease of grain size as Co content increased. The thermal expansion coefficient (TEC) tended to increase as Co content increased. In contrast, the monoclinic and orthorhombic structures were found in 20 and 40 mol% Fe-doped La0.84Sr0.16MnO3. The amount of second phase in sintered composition depends on the amount of Fe content. The conductivity at 1000 jC decreased, but the grain size increased as Fe content increased. The thermal expansion coefficient slightly changed with Fe addition.