A new lead borax glasses (PbO-Na2B4O7.10H2O) doped with Yb(III) is presented for the study of emission, absorption and other optical properties of borax glasses. Samples with different concentrations of Yb(III) were produced had their emission cross-sections, fluorescence lifetimes and minimum pump intensities determined. Changes in the position and the intensity parameters of the transitions are closely related to structural changes in the glass network. Specimen have high refractive index of 2.1 and a density of 4.2 g/cm3 for a doping level of 0.5%, the fluorescence lifetime after excitation at 930nm is 0.92ms this is comparable to Yb: telluride laser glass. So it is a possibility to explore a laser material for lasing purpose.