The mass attenuation coefficient (l/q), effective atomic number (Zeff), effective electron density (Ne,eff) and half-value layer (HVL) of xRmOn:(1 x)SiO2 glass system (where RmOn are Bi2O3, PbO and BaO, with 0.3 6 x 6 0.7 is fraction by weight) have been calculated by theoretical approach using WinXCom program in the energy region from 1 keV to 100 GeV.