Upconversion fluorescences at 525 nm, 550 nm and 660 nm wave-lengths were in generated in TeO2-PbO based tellurite glasses containing Er2O3 at ambient temperature. A diode laser operating at 804 nm was used as excitation source. The dependence of fluorescence intensity on pumping power fits to the quadratic profile which indicates the character of upconvorsion process. The influence of PbO contents in the glasses on the relative intensity of the upconverslon fluorescence has been estimated.