Ideas currently dominating the field of structural studies of TeO 2 -based glasses are critically considered. A new physically and chemically consistent approach to the constitution of binary TeO 2 –WO 3 glasses is proposed, in which the reasoning coming from the Raman spectra reexamination are correlated with the basic principles of thermodynamics. Separation into two phases is suggested in such glasses. One phase is TeO 2 , and another is Te(WO 4 ) 2 consisting of tetrahedral [WO 4 ] 2− anions and of Te 4+ cations. Supplementary M n O k oxides added to the glasses are found incorporated in the former phase, thus producing solid solutions (for M=Ti, Nb) or tellurite compounds (for M=Nd).