The structural and spectroscopic properties of Na_2O-Al_2O_3-SiO_2-xP_2O_5 glasses(x = 0 to 7 mol%) are investigated.Both Raman and IR spectra reveal that discrete phosphate species([PO_4]~(-3),[PO3O_(1/2)]~(-2)) with low polymerization degree can be formed in the silicate glass.These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network,resulting in an increase of the glass transition temperature.According to the Judd-Ofelt intensity parameters(Ω_2,Ω_4,Ω_6) of Er~(3+).the asymmetry of local environment around Er~(3+) becomes higher,and the bond covalency between Er~(3+) and O~(2-)decreases after P2O5 is introduced.In the emission spectra,photo-luminescence intensity increases with increasing P_2O_5 concentration and the spectra are inhornogeneously broadened,revealing that the ligand electric field around Er~(3+) is dramatically changed,and the glass matrix becomes disordered. The structural and spectroscopic properties of Na 2 O-Al 2 O 3 -SiO 2-x P 2 O 5 glasses (x = 0 to 7 mol%) are investigated. However, the Raman and IR spectra reveal that the discrete phosphate species ([PO 4] -3, [PO 3 O 1 / 2)] ~ (-2)) with low polymerization degree can be formed in the silicate glass. These phosphate structures scavenge non-bridging oxygen ions and cations from the silicate network, resulting in an increase of the glass transition temperature. According to (3+). The asymmetry of local environment around Er ~ (3+) becomes higher, and the bond covalency between Er ~ (3+) and O ~ (2-) decreases after P2O5 is introduced in the emission spectra, photo-luminescence intensity increases with increasing P_2O_5 concentration and the spectra are inhornogeneously broadened, revealing that the ligand electric field around Er ~ (3+) is dramatically changed, and the glass matrix becomes disordered.