Y(NO3)(3) and NH3 center dot H2O were used as a raw materials, and nano-Y2O3 powder was successfully synthesized by a precipitation method. Employing TEOS as a raw material, SiO2 powder was successfully prepared by a alkoxide-hydrolysis method, and a Y2O3/SiO2 composite powder was obtained by coating. The Y2O3, SiO2, and Y2O3/SiO2 powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectrophotometer (FT-IR); the Y2O3 and Y2O3/SiO2 powders were further examined by photoluminescence (PL) spectra. The results indicated that the Y2O3 powder had a body-centered cubic structure with an average size of 35 nm, while the SiO2 powder was amorphous, with an average size of 145 nm and a narrow size distribution. The PL spectra of the Y2O3 and Y2O3/SiO2 powders showed that their wavelength of emission spectra were 585 nm, while their wavelength of excitation spectra were in the range of 240-260 nm. The optical properties of the Y2O3/SiO2 powder were identical to the Y2O3 powder.