Amine-functionalized magnetic iron oxide nanoparticles (MIONPs-NH2) were successfully synthesized via a simple method, which exhibited excellent adsorbents properties for cationic-type heavy metals. The adsorption and desorption performances of Cue., Zn2+, Cd2+, Pb2+ and Ni2+ were fully investigated in detail and the possible adsorption mechanism was proposed on the basis of various characterizations as well as the adsorption priority. As a result, the MIONPs-NH2 could remove metal cations rapidly dependingon the complexation of amino groups on surface and the adsorption was both sensitive to pH and ionic strength. Moreover, the corresponding competitive adsorption processes and desorption experiments indicated that the as-synthesized sample has the strongest affinity and adsorption priority for Pb2+, followed by Cu2+ and Zn2+, and finally by Cd2+ and Ni2+. The present study may provide a helpful direction for the application of the MIONPs-NH2 in wastewater treatments involving multiple heavy metal cations. (C) 2017 Elsevier B.V. All rights reserved.