The spherical SiO2@Gd2O3∶Tb3+ core-shell luminescent materials with uniform size were successfully prepared by coating Gd2O3∶Tb3+ on the surface of silica nanospheres by a simple urea assisted precipitation method, which solves the common defects of rare earth luminescent materials, such as uncontrollable morphology and uneven size. The morphology, structure and luminescence properties of as-prepared samples were investigated by XRD, SEM, FT-IR and photoluminescence spectra. The SEM images and size distributions show that the as-prepared SiO2@Gd2O3∶Tb3+ particles exhibit uniform spherical morphology and good dispersion, and the particle size about (608±18)nm. XRD patterns show that the Gd(OH)3CO3 shell is completely transform into cubic phase Gd2O3 with good crystallinity and no impurity after calcination at 600 ℃. At the same time, the formation mechanism of SiO2@Gd2O3∶Tb3+ core-shell microspheres inferred by FT-IR spectra is concluded that Gd2O3∶Tb3+ shell is mainly connected to the surface of SiO2 microspheres by forming Si-O-Gd bond. Under the excitation of 240 nm ultraviolet light, the SiO2@Gd2O3∶Tb3+ core-shell microspheres show green emission peaks of Tb3+, and the main peak at 540 nm correspond to the 5D4→7F5 transition. The luminescence intensity of SiO2@Gd2O3∶Tb3+ core-shell microspheres reaches the maximum value when the doping concentration of Tb3+ is 4mol%, and the lifetime is 1.55 ms. The CIE color coordinates of SiO2@Gd2O3∶4%Tb3+ core-shell microspheres is located in the green region, showing good green light-emitting performance.