In this study, we re-verify the relationship between the structure and properties of cadmium phosphate glasses through the study of the optical and binding properties. We prepared cadmium phosphate glasses with various compositions, given by xCdO-(100-x)P2O5 (x=10-55 mol%), and analyzed their Fourier transform infrared spectra, X-ray photoelectron spectroscopy, optical band gap and other properties such as dissolution rate, thermal expansion coefficient, glass transition temperature, glass softening temperature. We found that the optical band gap and glass transition temperature decreased and thermal expansion coefficient increased with increasing CdO content. These results suggest that CdO acts as a network modifier in binary phosphate glass and weakens its structure. Futher, we found that the chemical durability and optical band gap is rapidly changed when the CdO content is more than 40 mol%. From these results, we can deduce that ionic bonding increases and covalent bonding decreases when the CdO content is more than 40 mol%.(Received Mary 16, 2014)