Mesoporous ceria with high specific surface area have been prepared using eerie ammonium nitrate and non-surfactants organic compounds glucose, acrylamide via hydrothermal method. The influence of the main synthesis variables have been studied, including cerium ion valence, composition of raw materials, hydrothermal temperature and time. XRD, TEM, TG and nitrogen adsorption techniques have been used to characterize the samples. Results indicate that cerium ion valence has the most important effect on surface area of mesoporous ceria. Cerium ion valence changing from +3 to +4 causes higher surface area of samples. Moreover the coexistence of glucose and acrylamide in the synthesis is essential to obtain samples with high surface areas, whereas surface areas of samples are lower in the absence of glucose or acrylamide. TEM shows that the mesoporous ceria are composed of three-dimensional disordered primary nanoparticles. The average size of primary particles and mesopores are both a few nanometers.