Abstract: A series of LaFe1-xCoxO3 oxygen carriers with different Co ratio were prepared by Citric acid complex method, and their properties were characterized by Thermal analysis, X-ray diffraction, Temperature program reduction and Scanning electron microscopy. The catalytic performance of the prepared samples was investigated in chemical-looping combustion of CO. XRD results showed that LaFe1-xCoxO3 oxides possessed perovskite-type structure. TPR results indicated that oxidizing ability of LaCoO3 was stronger than that of LaFeO3. Especially, the sequential redox reaction revealed that LaCoO3 oxide exhibits high oxygen delivery capacity after 10 redox cycles, in each cycle the CO conversion is 100%. Also the structure of LaCoO3 oxide didn’t change after 10 cycles besides new network structure which was formed under high temperature. All the results showed that LaCoO3 was suit to be oxygen carrier in chemical-looping combustion owing to its high activity and stability.