Eu3+(1at%) doped and Eu3+"(1at%), Y3+(10at%) codoped SiO2 glasses were prepared by sol-gel technology. Dominant red emission at 615 nm from 5D0to 7F2of Eu3+ was observed from both samples annealed above 800 °C. The intensity of luminescence of Eu, Y codoped samples is three times stronger than that of Eu doped samples. The lifetime of the former is two times longer than the latter. An analysis indicates that in the sample of Eu, Y codoped SiO2 glass, Eu3+ ions stay in the Y2O3 nanoclusters, which were formed during the annealing process and embedded in SiO2.