Chemically reduced graphene oxide (RGO) was synthesized from graphite powder (G) by using improved Hummer method. Graphene oxide (GO) was chemically reduced by using ascorbic acid to RGO. Reduction protocol was illustrated briefly. Typically, SEM, TEM, Raman and XRD characterizations were carried out to confirm the successful complete conversion of graphite to RGO. RGO. Additionally, G and RGO polyethylene (PE) composites were prepared by using different mass loading of 10, 20, and 30%. Electromagnetic measurements (8-12 GHz) were done for G and RGO and their composites. It was observed that average reflection losses (RL) decrease and the average transmission loess (TL) increase as the percentage of G and RGO increased from 10% to 30% in the composite matrix. The higher shielding optional of RGO composites with respect to corresponding G composites was attributed to the higher conductivity of RGO with respect to G. The highest TL average value was -45 dB for optimum mass percentage 30% RGO. The EMI shielding potentials of 30% RGO /PE may have promising EMI applications.