Abstract: In Hummers’ method and chemical co-precipitation method, an adsorbent of magnetic graphene oxide (M/GO) is synthesized, and used to remove Co(Ⅱ) from aqueous solution. With Hummers’ method and chemical co-precipitation method, M/GO has great saturation magnetization, and can be easily separated by an applied magnetic field. The investigation by batch sorption experiments indicates the sorption of Co(Ⅱ) on M/GO is pH-dependent and ionic strength-independent. The sorption equilibrium can be achieved within half an hour, and the kinetic sorption is fitted well by a pseudo-second-order rate equation. The high temperature is favorable to the sorption of Co(Ⅱ) on M/GO, and the sorption isotherm is described well by Langmuir model. The thermodynamic parameters indicate that the sorption is a spontaneous and endothermic process.