The effect of composition on the thermal stability and oxygen storage capacity (OSC) of a series of CeO2-MOx (M: Zr, Ti, Cu) mixed oxides was investigated. X-ray diffraction, N-2 adsorption-desorption analysis (BET), transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy were used to examine structural and microstructural properties. The total OSC of the fresh and aged mixed oxides were measured using thermogravimetric-differential thermal analysis at 600 A degrees C, under alternating reductive and oxidative environment. Ceria doping was found to be effective toward an enhancement of its redox properties. The addition of Zr4+ into the CeO2 lattice was found to have the least effect in enhancing the catalytic properties. In contrast with other studies in the literature [1, 2], increasing ZrO2 content led to an increase of the OSC of the samples of up to 522 mu mol O-2 g(-1) for 75 % Zr4+ content. On the other hand, the CeO2-CuO with (1:3) molar ratio showed an almost three times higher OSC value than CeO2-ZrO2, which is deemed in the literature as one of the most promising OSC materials. In this work, the highest OSC values (1565 mu mol-O-2 g(-1)) were obtained for the fresh sample with CeO2-CuO (25:75) composition. The CeO2-CuO (25:75) mixed oxide still showed the highest OSC values with an only 6 % drop of OSC after aging at 900 A degrees C for 6 h among all aged catalysts. On the other hand, ZrO2 containing samples showed the best thermal resistance against aging.