A new approach to synthesis of self-assembly CeO 2 nanoparticles by using microemulsion method was investigated. The structure of the product was characterized by the methods of X-ray diffraction (XRD), transmission electron microscopy (TEM), and extended X-ray absorption fine structure (EXAFS). XRD result indicates the face-center cubic(FCC) structure of the produced CeO 2 nanoparticles. EXAFS shows that the oxygen coordination number around Ce in CeO 2 nanoparticles decrease compared with the bulk CeO...