La0.7Sr0.3Fe0.1Mn0.9O3 and La0.7Sr0.3Fe0.4Mn0.6O3 perovskite were prepared via solid state reaction method for cathode application in solid oxide fuel cell. XRD analysis confirmed single phase and crystalline nature of the both compounds. Density was calculated by Archimedes Principle and surface morphologies were investigated via Scanning Electron Microscope. Thermal behavior of the compounds was studied by thermo gravimetric analysis and dilatometer. Above 350 0C temperature, material started gaining weight and increased content of Fe decreased its thermal expansion coefficient. Impedance spectroscope confirmed the non-Debye relaxation behaviour. Fe substitution enhanced the dielectric constant as well as conductivity and decreased the activation energy of the material. Maximum value of conductivity was found to be 116.31 S/cm for La0.7Sr0.3Fe0.4Mn0.6O3 compound. Investigated parameters recommended that as prepared materials are suitable materials for cathode of SOFCs.