Phosphate glasses of mol% xAl2O3:(40-x)Ag2O:60P2O5 have been prepared and studied by different techniques. X-ray diffraction measurement (XRD) has indicated the amorphous nature of the glasses. The hardness of the glasses increases with increasing Al2O3 concentrations. Data based on 27Al, 31P MAS NMR and Fourier transform infrared (FTIR) spectroscopy has been presented. The structural changes within the ternary phosphate glasses were correlated with that of the simple binary silver phosphate glasses. The obtained data led to suggest that aluminum plays a dual role, i.e., acts primarily as intermediate ions which means that Al2O3 enters the network of the glass both as a modifier and glass former. But silver oxide acts as a strong glass modifier. The number of non-bridging oxygen bonds (NBO) on average in the phosphate network decreases with increasing Al content. The Al2O3 in the structure of glasses exists in both Al(6) and Al(4). The concentration of Al(6) increases with increasing Al2O3 content. The concentration of Al(4) is much lower than that of Al(6) in the glass of 20 mol % Al2O3.