Powders of ceria-zirconia solid solution were prepared by using different molar ratio of Ce(NO₃)₄6H₂O and Zr(NO₃)₄5H₂O as raw materials and appropriate additives of C₃H₅NO, C₇H₁₀N₂O₂ and (NH₄)₂S₂O₈ as polymer -net gel. The influence of the polymer-net gel on the preparation process and the effect of Ce/Zr ratio on the properties of the powders of ceria-zirconia solid solution were investigated respectively. The results show that the additives of polymer are beneficial not only to the separation of the particulates of ceria-zirconia solid solution due to the formation of a three-dimensional network of the polymer-net gel, but also to the formation of nanoporous powders of ceria-zirconia solid solution due to the burn away of polymer during the subsequent calcinations. The powders of ceria-zirconia solid solution with particle size 10-20 nm could be prepared when the mass ratio of C₃H₅NO and C₇H₁₀N₂O₂ was 5: 1, the dissolvability of mixed solute was 0.04 mol/L and an appropriate heat treatment process was adopted. XRD analysis revealed that the ceria-zirconia solid solutions with molar ratio of Ce/Zr in a range of 3: 7-5: 5 present tetragonal crystallographic structure, while those in a range of 6: 4-7: 3 present cubic structure respectively; their lattice constant decreased with the increasing Zr⁺ content. N₂ adsorption isotherm showed that the ceria-zirconia solid solution with Ce/Zr molar ratio of 6: 4 exhibited excellent features: specific surface area of 120 m²g^-1; aperture of 8.12 nm; pore volume of 0.22 cm³/g. SEM images showed that the ceria-zirconia solid solution powders have an alveolate-like network structure.