NMR spectroscopy has been used for many years to investigate the structures ot glasses. NMR spectra have permitted the identification in the glasses of structorel groupings from the crystalline compounds, and the relationship of these groupings have also been determined by Krogh-Moe and Bray. According to computer calculated NMR data based on the experimental resulls in Na2O-B2O3-SiO2 system glasses, a new quantitative structural model from the principle of phase diagrams is proposed. We believe that the structiire of a simple glass resembles tire related coagrueni melting compound. A multlcomponent glass can be regarded as the melting mixtures of some nearest congrnent meliing compound in the phase diagram.