Terbium dioxide is intensively studied in luminescence and magneto optical applications. The fabrication and characterization of diamagnetic glass with composition of xTb 2 O 3 – 30PbO – 60Bi 2 O 3 – (10 − x) B 2 O 3 (x = 0, 0.1, 0.2, 0.4, 0.5 and 1 mol%) is reported. The influence of Tb 2 O 3 on glass forming ability, glass structure and properties has been studied by means of DSC, XRD, Raman, UV–vis/FTIR spectral and Faraday rotation measurement by a home-made optical bench. Due to the high optical basicity and high polarization of host glass, the formation of Tb 4 + in 0.1% Tb 2 O 3 doped PBB glass contributes to an improvement on density, refractive index, thermal stability (106 °C), optical cutoff wavelength (501 nm) and Verdet constant (0.1301 min/G·cm). [ABSTRACT FROM AUTHOR]