Er3＋/Tm3＋ codoped tellurite glasses with fixed amount of Tm3＋ (1.0mol%) and variable amounts of Er3＋ (0－1.5mol%) were prepared by melt-quenching technique and investigated by the differential scanning calorimeter (DSC),X-ray diffraction (XRD) and fluorescence spectra measurements.The DSC r esults reveal that the prepared glass samples possess good thermal stability with ΔT.(t he difference between the glass crystallization onset temperature and transition temperature) larger than 130℃ while the XRD patterns confirm the amorphous structural nature of glass system.Under the excitation of 808nm laser diode (L D),the 1.85μm band fluorescence of Tm3＋:³F₄→³H₆ transition increases si gnificantly with the introduction of Er3＋,and an improvement by about 76% of fluorescence intensity was observed in the glass sample with 1.0mol% amo unt of Er3＋,which is attributed to the energy transfers between Er3＋ and Tm3＋ ions.However,with the further increase of Er3＋ concentration,a fluorescence decaying phenomenon,mainly resulting from the concentration quench ing effect of Er3＋,occurred in the glass sample.The above results indicate that the prepared tellurite glass w ith appropriate codoped amounts of Er3＋/Tm3＋ ions is a promising host material applied for 1.85μm solid-state lasers and amplifiers.