The study aims to determine the oxygen transfer ability of cobalt lead (Co-Pb) mixed oxides during the thermal decomposition of Tuncbilek lignite under inert atmosphere. Thermodynamic calculations of reduction reactions of Co-Pb mixed oxides were performed to show the favorable reduction temperatures for the different reductive gases. Co and Pb mixed metal oxides were prepared by wet impregnation method and they characterized by X-ray diffractometer and Raman spectroscopy. Oxygen transfer performances of these oxides were evaluated by thermal gravimetric analysis (TGA) in terms of oxidation rates of lignite sample under N2 flows in the range of temperatures between 40 to 600ºC. The results of thermal gravimetric analysis (TGA) indicated that the optimum coal to Co-Pb metal oxides ratio based on oxidation efficiency was 0.11.