Polymer electrolyte membranes comprising poly(vinylidene fluoride) (PVdF), poly(methylmethacrylate) (PMMA), LiClO4 and DMP were prepared. Structural characterization was carried out on the polymer electrolyte thin film using XRD. The complex formation of polymer and salt has been confirmed by XRD and FT-IR spectral studies. The ac conductivity studies were performed to evaluate the ambient temperature conductivity of the polymer electrolyte membranes. The influence of blend compositions on the ionic conductivity was discussed. The maximum conductivity for PMMA (7.5)-PVdF (17.5)-LiClO4 (8)-DMP (67) system is found to be 4.2 x 10(-3) S cm(-1) at 303 K. (C) 2002 Elsevier Science B.V All rights reserved.