Mesoporous cerium dioxide was synthesized using the ordered mesoporous silica SBA-15 as a hard template. The IR, XRD, TEM, nitrogen sorption measurement, and EDX techniques have been adopted to characterize those materials. The hard template silica was synthesized by hydrothermal method in acidic medium using TEOS and P123 as the silica precursor and structure directing agent, respectively. In order to seek the appropriate SBA-15 for fabrication of porous CeO2 replica, two methods including extraction with ethanol and calcination of as-synthesized SBA-15 were applied to eliminate the P123 template. IR and small-angle XRD methods showed SBA-e as the preferred candidate for preparing porous CeO2. The silica hard template in composite CeO2/SiO2 was successfully dissolved by treating with hot NaOH solution and the contamination was examined by using EDX analysis. The obtained mesoporous CeO2 replica owned the hexagonal structure with highly ordered arrangement of pores. The wide-angle XRD method elucidated the crystalline nature of pore wall that constructed the structure of porous CeO2 material.