Five samples of tellurite glasses with the system of (78-x) TeO2-10PbO- 10Li2O-2Nd2O3-xEr2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 mol % have been prepared by using the conventional melt-quenching method. In this work, the optical properties by mean of their up-conversion luminescence as well as the optical parameters related to Judd-Ofelt theory were measured. The result reveals that six distinctive up-converted bands contributed from Nd3+ ions are observed to be centered at 485 nm, 605 nm, 665 nm, 880 nm, 1062 nm and 1340 nm attributed from 4G11/2 → 4I11/2, 4G11/2 → 4I15/2 , 4G7/2 → 4I13/2 , 4F3/2 → 4I13/2 , 4F3/2 → 4I11/2 and 4F3/2 → 4I9/2 transitions whereas, three upconverted bands contributed from Er3+ ions to be centered at 493 nm, 524 nm and 550 nm are found originating from 4F7/2 → 4I15/2, 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions under the excitation at 585 nm. Meanwhile, the optical parameters according to Judd-Ofelt theory such as the radiative lifetime τR, stimulated emission cross-section σeff, and the non-radiative relaxation W nr of the glass were found ranging from 0.812ms to 1.248ms, 0.812 x 1020 cm2 to 1.248 x 1020 cm2 and from 0.144 ms-1 to 0.180 ms-1 respectively with respect to mol% of composition . Further analysis and discussion will be elaborated in brief.