Under different annealing temperatures, Eu 3+ doped SiO 2 gel and glass were prepared by sol gel method, and the structure and luminescent properties were studied with excitation spectra, emission spectra, IR and DTA TG. The results show that the fluorescent intensity tends to get stable when concentration of Eu 3+ doped is above 1 86 % (mass fraction) most water absorbed by the gel was removed at 300 ℃, and that the emission spectrum of Eu 3+ , with peaks at 614, 588, 577 nm, is due to 5D 0→ 7F 2, 5D 0→ 7F 1, 5D 0→ 7F 0 transitions, and the excitation peaks at 318, 362, 380, 393, 412 and 462 nm were observed. These results illustrate that the temperature range of 300～500 ℃ is critical for the structure conversion from gel to glass, and the fluorescence is strongly quenched by water. Under different annealing temperatures, Eu 3+ doped SiO 2 gel and glass were prepared by sol gel method, and the structure and luminescent properties were studied with excitation spectra, emission spectra, IR and DTA TG. The results show that the fluorescent intensity tends to get stable when concentration of Eu 3+ doped is above 1 86% (mass fraction) most water absorbed by the gel was removed at 300 ° C, and that the emission spectrum of Eu 3+, with peaks at 614, 588, 577 nm, are due to 5D 0 → 7F ​​2, 5D 0 → 7F ​​1, 5D 0 → 7F ​​0 transitions, and the excitation peaks are 318, 362, 380, 393, 412 and 462 nm were observed. These results illustrate that the temperature range of 300 to 500 ° C is critical for the structure conversion from gel to glass, and the fluorescence is strongly quenched by water.