Tm3+ single doped and Tm3+/Yb3+ codoped tellurite glasses with the composition of TeO2ZnONa2O were prepared by meltquenching method. The intensity parameters Ωt(t=2, 4, 6), spontaneous radiative transition rates A, fluorescence branching ratios β and radiative lifetimes τrad of Tm3+ were calculated based on the JuddOfelt theory, and the upconversion luminescence of Tm3+ for glass sample with different Yb3+ doping concentration was measured. The results show that the glass sample can emit strong nearinfrared upconversion emission under the excitation of 980nm pump light. The analysis of Tm3+ upconversion emission process reveals that the intense nearinfrared upconversion luminescence of Tm3+ ions is mainly ascribed to the result of energy transfers: first the resonant energy transfer from Yb3+ to Yb3+ ions, and then followed by one and two phononassisted nonresonant energy transfer from Yb3+ to Tm3+ ions. The energy transfer coefficient and phonon contribution for the above energy transfer process were calculated. Furthermore, the 1.8μm band absorption, emission crosssections and gain coefficient of Tm3+∶3F4→3H6 transitions were calculated and analyzed. The research indicates that Yb3+/Tm3+ codoped TeO2ZnONa2O glass is a promising host material applied for nearinfrared band solid laser.