Graphene/beta-MnO(2)composites were synthesized via ultrasonication method, followed by calcination at 400 degrees C for 4 hours. The structural properties of synthesized graphene and graphene/beta-MnO(2)composites were systematically studied using different instruments, such as XRD, FESEM, TEM, EDX, XPS and FT-IR spectroscopy. Furthermore, magnesium storage performance was scientifically studied using various electroanalytical characterizations like galvanostatic charge/discharge, electrochemical impedance spectra and cyclic voltammetry. The GNS/beta-MnO2-20% composite displays the discharge capacity of 110 mAh/g within 60 cycles at a current density of 25 mA/g, which is an excellent rate capability, and magnesium storage performance around 100 cycles. There is a significant improvement in electrochemical properties of GNS/beta-MnO2-20% composite materials as cathode for magnesium storage system due to the synergetic interaction between a pure beta-MnO(2)particle and graphene sheet.