Glasses of composition xBi2O3-(83-x) B2O3-15Na2O-2MnO2 with (x =0, 5, 10, 20 and 25 mol %) have been prepared by conventional melt quench technique. Characterization of the prepared samples has been achieved by X-ray diffraction (XRD), density and optical measurements. The XRD patterns of all the samples showed broad humps typical for amorphous systems. Density and molar volume have been determined and it is found that both are increased with increasing of Bi2O3 content. The effect of Bi2O3 content on the optical absorption spectra was investigated in the wavelength range190-1100nm.The fundamental absorption edge has been identified where it exhibits red shift by increasing Bi2O3 content and band tail width follow opposite trend. The optical band gap (Eg) values of the investigated glasses are found to lie in the range 2.40 – 1.90 eV whereas the values of (ΔEe) lie in the range 0.66 – 1.436 eV. Some other physical properties also reported.