The tellurite glass 70TeO2-20WO3-10ZnO in different Tm3+-doping co ncentration were prepared. According to the absorption spectra,the Judd-Oflet strength parameters were calculated by using Judd-Ofelt theory. The spontaneous-emission probabilities,branch ratios and radiative lifetime of each level of Tm3＋ were given.The emission spectra of Tm3＋-doping in various concentrations were studied.The effective bandwidth and stimulated emission cross-section at the peak wavelength of the emission band were also investigated. Aft er comparing the spectral properties at various Tm3＋ concentra tions, we concluded that the luminescence intensity and effective bandwidth were maximum when the Tm3＋-doping concentration ranges from 0.8wt%—1wt%. The Tm3＋-doped tellurite glass is an ideal host for optical ampli fier working on S-band.