Abstract: Tellurite glass doped rare earth is a kind of important material used in fabricating broadband fiber amplifiers. It has the properties of wide transmission region, good stability and so on. We discussed the radiative lifetimes of rare earth ions(Pr~(3+),Er~(3+)) in tellurite glasses while the diode-pumped laser is at 980nm. We selected a 100MHz digital oscilloscope to monitor the fluorescence decay in the radiative lifetime measurement and calculated the radiative lifetime with the dacay data obtained from the oscilloscope through the fitting calculation of the least square method.