A sodium borate glass containing both trivalent cerium oxide and tetravalent cerium oxide states nano particles of 2–5 nm in size was successfully prepared by doping the glass with varying amounts of cerium (IV) oxide with. X-ray absorption spectroscopy measurement was used to determine the coexistence of the multivalent state of cerium oxide in the borate glass. Significant changes in the trivalent and tetravalent cerium oxide concentrations were observed when the glass was melted using different melting parameters and different raw materials. Glass made with borax that contained of 0.05mols of CeO2 and melted at 1100 °C for 3 h had the highest concentration of trivalent cerium oxide. Transmission electron micrographs confirmed the release of trivalent Ce2O3 and tetravalent CeO2 nanoparticles from the glassy matrix. Fourier transform Infrared measurements suggest that the CeO2 in the glass acts as both a glass-former and glass modifier.