We synthesized 2D graphene oxide with Hummers' method,endowed the graphene oxide with magnetism by Fe3O4that was prepared by in situ synthesis,and finally obtained magnetic graphene oxide with high magnetism and good adsorption efficiency for cupric ion. In the synthesis,alkaline liquor was replaced with NH3·H2O-NH4Cl buffer solution. This overcame the drawback from traditional ways in which the property of products is compromised due to the continuous decrease in the pH value of systems. The result of TEM showed that the magnetic graphene oxide possessed excellent 2D layered structure. The results of magnetic property and adsorption experiment showed that the magnetic graphene oxide had strong magnetism and outstanding adsorption efficiency for cupric ion.The result of adsorption kinetics suggested that the adsorption is a process of pseudo second kinetics and has an adsorption way where chemical adsorption mechanism controls the speed.