Polymer electrolyte membranes comprising of poly (ethyl methacrylate)/ poly (vinyl chloride), propylene carbonate (PC) as plasticizer and LiClO4 as salt were prepared by solvent casting technique. XRD, FTIR and SEM studies have been made to investigate the structural, complexation and variation in film morphology of the polymer electrolyte. The maximum ionic conductivity value 3.454x10-3 S/cm has been observed for PVC (5)-PEMA (20)-PC (67) - LiClO4 (8 wt %) system at 303K using ac impedance spectroscopic technique. Also, the TG/DTA studies showed the thermal stability of the film ©2008 by ESG.