The morphological control of cerium oxide particles was carried out by a homogeneous precipitation followed by calcination in air at 400°C. The effects of pre-aging temperature, aging time and precipitation reagents on the morphologies of final products were investigated. When urea was used as a precipitation reagent, monodispersed spherical and flake-like cerium carbonate hydroxide precursor was precipitated in the solution at 90°C for 2 h after pre-aging at 25°C-50°C for 24-72 h. On the other hand, monodispersed nanosize rod-like cerium hydroxide particles were obtained using triethanolamine as precipitation reagent. Ceria particles with the same morphologies and slightly smaller particle size than those of as-prepared cerium precursor could be obtained after calcination in air at 400°C. Physical-chemical characteristics of the monodispersed cerium oxide particles were evaluated.