Nano-sized CeO2 powders have been synthesized using three different methods of emulsion: (1) reversed micelle (RM); (2) emulsion liquid membrane (ELM); and (3) colloidal emulsion aphrons (CEAs) with the same starting materials. The powder was calcined at 500 C to obtain CeO2. The effect of the preparation procedure on the crystallite size, surface area, and the morphology of the prepared powders have been investigated. The results show that CeO2 powders prepared by different methods all possess the same cubic fluorite structure and highly crystalline. The average particle size and the specific surface area of the powders from the three methods are in the range of 4-10 nm and 5.32-145.73 m(2)/g, respectively. The CeO2 powders synthesized by CEAs method are the smallest average particle size and the highest surface area. Finally, the CeO2 prepared by the CEAs method using different cerium sources and surfactant types have been studied. It was found that the surface tensions of cerium solution and the type of surfactant affect the particle size of CeO2.