In this present study, nanocomposite polymer films are prepared based on PVP and MgBr2 with doping of additive plasticizers (Al2O3) with different ratios using olution cast technique. XRD pattern confirms the semi crystalline nature of the polymer films. The ionic conductivity of the prepared films was measured by using AC impedance spectroscopy and it is found to be at 10-2 S/cm. The electrical conductivity studies were carried out by DC ionic conductivity set up and for the composition of 85 (PVP):15(MgBr2):0.1(Al2O3), the highest ionic conductivity was found to be at 1.2510-2 S/cm at room temperature. The conductivity is found to increase with increase in temperature. The temperature dependent conductivity of the polymer electrolyte follows the Arrhenius relationship which shows hopping of ion mechanism in the polymer matrix.