Silver ion conducting glasses composed of (AgI)x-(Ag2WO4)1-x (x = 0.80-0.55) were prepared by a rapid melt quenching method. Their physical properties were investigated by X-ray, DSC, impedance and Ag-109 NMR measurements. The glass transition temperatures were in the range from 110°C to 187°C. The glasses show unusually high ionic conductivities of 2.5 × 10-3 S/cm at x=0.55 and 2.3 × 10-1 S/cm at x=0.80, which varied exponentially with increasing AgI content. Ag-109 NMR spectra also support the high mobility of silver ions in the glasses. Structures of the glasses were investigated by FTIR and W-L1 edge XANES. From these results it is concluded that the tungsten ions are octahedrally coordinated by oxygen ions as in crystalline Ag2WC4 and Ag26I18W4O16, which is quite different from the structure of AgI-Ag2MoO4 glasses.