The present study proposes a novel reverse precipitation procedure, which is different from the conventional precipitation method, for the synthesis of ultra high surface area mesoporous CeO2 at various conditions. Mesoporous Ni2xCe1-xO2 (x = 0.05, 0.13, 0.2) is also synthesized for use in the methane steam reforming reactions. The physicochemical properties of the catalysts and catalytic activity tests for the steam reforming of methane are also investigated. In the present study, the preparation of high surface area mesoporous CeO2 is proposed, which successfully enables control over the surface area. The results showed that the highest surface area of mesoporous ceria reached 695 m2/g. Tests on long-term catalytic activities indicated that Ni0.4Ce0.8O2 exhibited a much greater stability and activity for the steam reforming of methane than the others. Further, the present work also found that the amount of mobile oxygen increased simultaneously as the nickel content in the proposed catalysts due to the synergistic effects of structural nickel species to the oxygen vacant sites at the vicinity of the surface. Using the proposed new method, mesoporous ceria can be utilized more extensively in many ways, including as a three-way catalyst, as an electrolyte of solid oxide fuel cells, in reforming reaction, and in some other practical applications.