Reduced graphene Oxide (RGO) was synthesized from treated Borassus Flabelifer L. The Isotherms adsorption kinetics of methylene blue on RGO was studied in this research. Borassus Flabelifer L as the raw material was heated at 650°C, 750°C, 850°C for 2 hours with the flowing of nitrogen gas. X-Ray Diffraction (XRD) used to clarify the RGO phase. The surface morphology was characterized by Scanning Electron Microscopy (SEM), meanwhile the absorbance of methylene blue on RGO studied by UV-Vis Spectrophotometry. The surface area of RGO with 70.31 m2/gr; 110.90 m2/gr and 25.52 m2/gr when heated at 650°C, 750°C, and 850°C, respectively. The RGO phase was obtained through the XRD measurement at all activation temperatures. SEM and surface area measurement proved that the activation temperature of 750°C, was the optimum temperature where the RGO has more pores and a larger surface area. Based on the study of adsorption kinetics, the highest adsorption efficiency was obtained at 850°C.