Transparent glasses were synthesized in the NaPO 3 –BaF 2 –WO 3 ternary system and several structural characterizations were performed by X-ray absorption spectroscopy (XANES) at the tungsten L I and L III absorption edges and by Raman spectroscopy. Special attention was paid to the coordination state of tungsten atoms in the vitreous network.XANES investigations showed that tungsten atoms are only six-fold coordinated (octahedra WO 6 ) and that these glasses are free of tungstate tetrahedra (WO 4 ).In addition, Raman spectroscopy allowed to identify a break in the linear phosphate chains as the amount of WO 3 increases and the formation of P–O–W bonds in the vitreous network indicating the modifier behavior of WO 6 octahedra in the glass network. Based on XANES data, we suggested a new attribution of several Raman absorption bands which allowed to identify the presence of W–O − and WO terminal bonds and a progressive apparition of W–O–W bridging bonds for the most WO 3 concentrated samples (⩾30% molar) due to the formation of WO 6 clusters.