Mesoporous structured CeO2 with high specific surface area was synthesized at ambient temperature in this study. The synthesis of this material was accomplished using a tri-block copolymer as the organic supermolecular template and the cerium nitrate hexahydrate as the inorganic precursor. X-ray diffraction, nitrogen adsorption and desorption isotherms and transmission electron microscopy have been used to characterize the mesoporous structure. The nitrogen adsorption and desorption isotherms analysis indicates that the average pore size is 3.5 and 3.4 nm and the specific surface area is 155 and 103 m(2)/g for the samples calcined at 523 and 723 K, respectively. (C) 2004 Elsevier Ltd. All rights reserved.