Abstract: Er3+ doped niobate-tellurite glasses(EDTNb) are prepared, whose host compositions are TeO2,Nb2O5,ZnO and Na2O.The di fferential thermal analysis (DTA) curves of the glasses show that the thermal stability of EDTNb glasses against crystallization increases due to the introducti on of 4% Nb2O5.The measured absorption spectra are analyzed by McCumber theo ries in order to obtain the spectroscopic properties of the glasses.It is found that the peak stimulated emission crosssection of EDTNb glasses is 8.9×10-21cm2, which is 8% larger than that of tellurite glasses.