A new type of Ruddlesden?Popper cobalt?rich layer perovskite oxide La_1.5Ca_0.5Ni_0.2Co_0.8O_4+δ (LCNC) was synthesized by a sol?gel process. The results show that the conductivity of LCNC in air at 400 ℃ to 800 ℃ is 4~58 S/cm, which is better than that of most reported SOFC cathode materials. The polarization impedance of symmetrical battery LCNC|LSGM|LCNC is 0.16 Ω·cm² at 800 ℃. The maximum power density of the single cell supported by 300 μm thick La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ (LSGM) with the LCNC cathode was 527 mW/cm², and the performance of the single cell decreases slightly after working continuously for 50 hours. The experimental results show that LCNC is a potential SOFC cathode material.