A novel material of Ce0.7Zr0.3Ba0.1O2.1 with diameters between 30 and 50mn was firstly synthesized by a macromolecule surfactant modified method. The physical and chemical properties of Ce0.7Zr0.3Ba0.1O2.1 nanoparticle powder were investigated. The morphology of the prepared nanoparticle powder was investigated by transmission electron micrographs (TEM) and atomic force microscopy (AFM). The experimental results described that the new Ce0.7Zr0.3Ba0.1O2.1 nanoparticle powder showed an optimal thermal stability, high surface area and novel catalytic performance for CO total oxidation than Ce-Zr solid solution reported previously. (c) 2005 Elsevier B.V. All rights reserved.