Tungsten-tellurite glasses with the molar compositions of (60+x)TeO2-(30-x)WO3-8BaO-2Na2O-0.5Er2O3 (x=0,5,10,15,20) have been prepared. Effects of WO3 on optical properties of Er3+-doped tungsten-tellurite glasses have been discussed. Along with the WO3 content increasing, Ω2 and Ω6 first increase and then decrease, and the stimulated emission cross-section also behaves in like manner, while Ω4 changes contrarily. According to the McCumber theory, the maximum peak of σe is calculate to be 1.00×10-21cm2 at 1.55μm. The maximum FWHM of Er3+ 4I13/2→4I15/2 emission spectrum is 82nm. In addition, the intensity of upconversion luminescence of the Er3+-doped tungsten-tellurite glasses decreases rapidly with the increasing of WO3 content.