Nanometer cerium (IV) oxide (CeO2) powders were prepared by means of different methods, Sol-Gel method, precipitation method and electrochemical method. The powders were analyzed by using X-ray diffraction (XRD), transmission electron micrograph (TEM), scan electron micrograph, small angle X-ray scattering (SAXS). The powders on different methods were compared from the shapes of particles, preparation techniques. The features of every preparation method were introduced and its developmental trend was also predicted.