CeO2 thin films were grown on Si(100) and Si(111) substrates by radio frequency-magnetron sputtering. The growth temperature and the substrate orientation have significant influences on the preferred orientations of deposited CeO2 films. X-ray diffractometry and transmission electron microscopy analyses showed that CeO2 on Si(111) has a better preferred orientation in the direction of the substrate orientation than CeO2 on Si(100). CeO2 films deposited on Si(111) substrates maintain a preferred orientation better than CeO2 films on Si(100), when they are subjected to annealing at 900 degrees C in O-2 atmosphere for 30 min. Rutherford backscattering spectra taken of CeO2/Si before and after annealing showed that CeO2 has strong thermal stability.