Functionalized graphene nano-platelets (FGN) were obtained via treating graphene nanoplatelets (GN) with HNO3, and served as adsorbent for the removal of Pb2+ from solutions. We investigated the FGN adsorption capacity for Pb2+ at different initial concentrations, varying pH, contact time and temperature. The characterization results of scanning electron microscopy (SEM), thermal analysis (TG/DTG), Fourier transform infrared spectroscopy (FT-IR) and Brunauer-Emmett-Teller (BET) method indicated that FGN layers were thin and possess large specific area with oxygen-containing functional groups grafted onto their surface. Meanwhile, the determined equilibrium adsorption capacity of FGN for Pb2+ was 57.765 mg/g and adsorption isotherms well confirmed to Langmuir isotherms models. The results reveals that the FGN has better effect of water treatment.