Abstract: The spherical nano-sized Y2O3 powders were prepared by homogeneous precipitation method，with urea as the pre- cipitating agent，Y（NO3）3 as the yttrium source，and CTAB as the dispersant.The effects of reactants concentration ratio，dis- persant dosage，reaction time，reaction temperature，and stirring rate on the morphology and particle size of Y2O3 powders were investigated.The samples were characterized by laser particle size analyzer，X-ray diffraction（XRD），scanning electron microscopy（SEM），and Fourier transform infrared spectroscopy（FTIR）.Results showed that the reactants concentration ratio， reaction time，stirring speed，and reaction temperature will affect the size of the powders，and the suitable addition of CTAB could reduce the particle size of Y2O3 significantly.Under the conditions of optimum process，the particle size of Y2O3 powders was about 110~130 nm.

Key words: homogeneous precipitation method, spherical nanometer Y2O3, urea, CTAB