Highly oxygenated graphene oxide was synthesized. Ethylenediamino graphene oxide (EDAGO) with many amino and hydroxyl groups was prepared for adsorbing heavy metal ions in wastewater. The maximum adsorption capacities of EDAGO for Pb(II), Cu(II), Ni(II), Zn(II) and Co(II) were 740.7, 97.0, 84.1, 70.8 and 68.2mg/g, respectively, when pH values were 5.0, 4.0, 5.0, 5.0 and 5.0, respectively. Removal efficiencies of EDAGO for Pb(II), Cu(II) and Zn(II) were 99.2%, 95.8% and 93.9%, respectively; moreover, the adsorbent can be reused and exhibits very high removal efficiencies.