In this study, a method to improve the chemical mechanical polishing (CMP) performance of ceria as abrasive particles was proposed. Surface doping of ceria nanoparticles was realized by incipient impregnation method, in order to improve its valance change properties (Ce3+/Ce4+). This study presents detailed characterization of the lanthanide-doped CeO2 by both experimental methods and density functional theory (DFT) calculation. The dispersion stability of the doped ceria nanoparticles in CMP slurries are investigated. Results show that the doped CeO2 nanoparticles exhibit more oxygen vacancies and higher content of Ce3+ compared with the pristine CeO2. Good dispersion stability of the doped CeO2 nanoparticles could be achieved by adding dispersants in the CMP slurries.