The Ruddlesden?Popper (RP) perovskitetype composite cathode material was prepared by a sol?gel method,and the performance of using it as a SOFC cathode was evaluated.XRD result shows that the composite material calcined at 1 200 ℃ was (La_2/3Sr_4/3)FeO₄?(La_4/3Sr_8/3)Fe₃O₁₀ (LSF).At 400 ℃,the highest conductivity of the sample is 57.0 S/cm in air.At 800 ℃,the interfacial polarization resistance of the LSF electrode on La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ (LSGM) electrolyte is 0.198 Ω·cm².Based on a single cell supported by a 300?μm?thick LSGM,the peak power density of the sample when used as a cell cathode was up to 670 mW/cm² when used as the cathode of the cell, with no performance degradation for 50 h of continuous operation.Experiments show that the LSF cathode has excellent and stable electrochemical performance,and is a very promising cathode material for SOFC.