The CeO2/Co3O4 catalysts were prepared via the microemulsion method, and characterized by XRD, BET, H-2-TPR and TG-DSC techniques. It is found that the low precursor concentration can form high surface area when preparing the Co3O4 supports, which is favorable for the dispersion of CeO2 to generate CeO2 particles with small crystallite sizes. The good reducibility not only produces more metallic cobalt to improve CH4/CO2 reforming, but also helps CeO2 realize the redox cycle via the mobility of lattice oxygen. The 0.2PCCeO(2)/Co3O4 has better catalytic performance due to its small crystallite sizes of CeO2, high surface area and good reducibility.