采用以柠檬酸为配体的溶胶———凝胶法制备了 Ｃｅ Ｏ２ 超细粒子．考察了不同制备条件（ 金属离子与配体的摩尔比、反应温度、ｐ Ｈ、凝胶烘干温度、焙烧温度及时间） 对粒子的影响，获得了最佳的制备条件：金属离子与配体的摩尔比为１ ：３ 、反应温度为６５ ℃、ｐ Ｈ＜ ０（ 未调） 、凝胶烘干温度为６５ ℃、３２０ ℃焙烧温度２ｈ ．并在该条件下成功地制得了均匀分散的 Ｃｅ Ｏ２ 超细粒子（ 平均粒径为１０ｎｍ ，比表面为５７ ｍ ２／ｇ） ． CeO2 ultrafine particles were prepared by sol-gel method using citric acid as ligand. The effects of different preparation conditions (mole ratio of metal ions to ligand, reaction temperature, p H, gel drying temperature, calcination temperature and time) on the particles were investigated. The optimal preparation conditions were obtained: Molar ratio of 1: 3, reaction temperature of 65 ℃, p H <0 (untreated), gel drying temperature of 65 ℃, 320 ℃ calcination temperature 2h. Under these conditions, uniformly dispersed Ce O2 ultrafine particles (average particle size 10 nm, specific surface area 57 m 2 / g) were successfully prepared.