Er3+/Yb3+ co-doped tungsten-tellurite glasses, 65TeO2 -25WO3-10RmOn(RmOn= PbO,BaO), (65+x) TeO2-(25-x)WO3- 10La2O3(x=0,5,10),(60+x)TeO2-(30-x)WO3-10Bi2O3(x=0,5,10) have been prepared. The thermal stability and spectral properties, such as absorption spec tra, emission spectra and lifetimes of the 4I13/2 level of Er3+ were investigated. Results obtained show that tungsten-telluri te glasses have good thermal stability. All the glass samples except the Bi2O3-containing g lasses show no onset temperature of crystallization (Tx), indicating that they are stable for fiber drawing. Three intensity parameters Ωt(t= 2,4, 6) were calculated by Judd-Ofelt theory. It is shown that Ω2 is domi nated b y the covalency between the Er3+ and O2-, the effect of as ymmetry in the local structures around the Er3+ ions on Ω2 can be neglected. The full width at half maximum (FWHM=71—77 nm) of the 4I 13/2→ 4I15/2 emission and lifetimes of 4I 13/2 level(τm= 3—3.4 ms) of Er3+ ions were measured. The emission cross-section ( σpeak=068—103×10-20 cm2) of the 4I13/2→4I15/2 transitio n of Er3+ ions were calculated according to the McCum ber the ory. The FWHM and emission cross-section of Er3+ ions at 1.5 μm ba nd in d ifferent glass hosts were compared. The results show that tungsten-tellurite gla ss will be the promising host material for 1.5 μm broadband amplification.