The authors synthesized the core-shell nanoparticles of SiO2-coated SiO2∶Tb3+ by using sol-gel method (SiO2∶Tb3+@SiO2), and studied the influence of core-shell ratio and preparation craftwork on its luminescence properties. The photograph of TEM and EDS showed that SiO2∶Tb3+ were coated successfully by SiO2. The authors found that the samples of SiO2∶Tb3+@SiO2 prepared by mixing of core and shell after shell aging with the ratio of core/shell being 1.2 g/25 mL had the stronger fluorescence intensity. Time-resolved spectra showed that the SiO2∶Tb3+@SiO2 had longer fluorescence life time than SiO2∶Tb3+.