The upconversion emission characteristics of Er3+/Yb3+–codoped tellurite glasses pumped by 975 nm LD at low temperature is reported. Intense upconversion emission signals around 529 nm, 546 and 669 nm corresponding to the 2H11/2,4S3/2, and 4F9/2 transitions to the 4I15/2 ground state are observed. The green (546 nm) and red (669 nm) upconversion fluorescence has a maximum intensity enhancement of 2.198 and 1.556 times around 80 K. A monotonic decrease behavior is observed for temperatures greater than 80 K. In the same temperature range the signal at 529 nm vanishes towards the lower temperature side. Population of 4S3/2 and 2H11/2 distribution as a function of temperature are investigated and fitted well by the calculated lines. Temperature dependence of luminescence lifetimes of the 4S3/2 and 4F9/2 levels of Er³⁺ are studied within the temperature from 8 K to 300 K and the 4S3/2 and 2H11/2 multiplets splits are investigated by a multi-Gaussian-fit procedure.