We have investigated the temperature dependence of unit-cell and structural parameters of ceria (cerium dioxide, CeO2) from room temperature to 1770 K by neutron powder diffraction and the Rietveld method. The unit-cell parameter increases continuously with temperature. It was confirmed that the Debye-Waller factor of oxygen B(O) is larger than that of cerium B(Ce) at any temperature from room temperature to 1770 K. Both B(O) and B(Ce) increase with an increase of temperature. (C) 2003 Elsevier Science B.V. All rights reserved.