Well-crystalline ceria particles were synthesized by heating peptized ceria sol as precursor under hydrothermal conditions. The morphology and the crystallites size of hydrothermal ceria particles were controlled by varying the dielectric property of solvent used in preparation of the ceria precursor. The synthesized particles exhibit cubic fluorite structure with size ranged from 20 to 400 nm without the formation of hard aggregates. In this work, the relationships between dielectric property of the solvent and particle size were investigated in terms of the supersaturation of solute. In addition, the influences of precipitation participating anions (OH-) and acidic hydrothermal medium on crystallites size of ceria particles were studied. (C) 2010 Elsevier B.V. All rights reserved.