The structure factor S(Q) of superionic conducting (AgI)(x)(AgPO3)(1-x) glasses (x=0.1, 0.3, 0.5) has been investigated at 15, 100, 200 and 290 K by X-ray diffraction measurement. The temperature and composition dependence of the effective overall Debye-Waller temperature parameter B and mean-square displacement of atom have been discussed based oil the theoretical treatment including the thermal vibration of atoms in noncrystalline materials. The values of the effective overall Debye-Waller temperature parameters B-T-B-15K increase with the increase of temperature and the composition of AgI concentration. (C) 2004 Elsevier B.V. All rights reserved.