A series of binary tellurite based glasses (Bi₂O₃)_x (TeO₂)_100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi³⁺ increase, this is due to the increased polarization of the ions Bi³⁺ and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, E_opt decreases while the refractive index increases when the ion Bi³⁺ content increases.