Solid polymer electrolytes (SPEs) formed by distribution of alkali metal salts in polymer play an important role in the development of new energy sources, like solid state batteries, photo-electrochemical solar cells, sensors and electrochromic displays. Technological application of this class of materials requires high ionic conductivity (10-3 S cm-1). Many research groups have endeavored for over three decades to synthesize the polymer with high conductivity but so far the conductivity of more than 10-3 S cm-1 has not been achieved. The main hurdle to achieve the goal is incomplete understanding of conduction mechanism in polymer electrolyte. The frequency dependent conductivity and dielectric relaxation both are sensitive to the motion of charged species and the dipoles of the polymer electrolyte. Their studies provide important information on the ionic transport mechanism of fast ion conductors. In this context, the present work is taken to explore the ion dynamics in Poly methyl methacrylate (PMMA) - LiClO4 based polymer electrolyte using the analysis of frequency dependent dielectric relaxation and conductivity. Polymer electrolyte films have been prepared by solution cast technique. The dielectric behavior of the films has been analyzed in terms of frequency response of dielectric permittivity (ε’) and dissipation factor (tanδ). Such an analysis has confirmed the presence of electrode polarization at lower frequency. The appearance of the loss peak in the low frequency (mHz to a few Hz) region is attributed to the losses due to conduction. The real part of ac conductivity spectra of the materials obeys Jonscher power law. It has been observed that the increase of salt concentration reduces the ionic conductivity relaxation time and hence increases the ionic conductivity. A correlation between ion hopping rate (ωp) and carrier concentration term (K) has been achieved from experimental results. The analysis appears to be consistent with the observed conductivity variation.