Polyethyleneimine (PEI)/graphene oxide (GO) was synthesized through a self-assembly method with the formation of the amide group -CONH- between -NH2 on PEI and -COOH on GO. The formation was confirmed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The oxygen and nitrogen-containing functional groups of PEI/GO were involved in the adsorption of U(VI), as determined under the FT-IR and XPS analyses of PEI/GO and U(VI)-adsorbed PEI/GO. The pH, contact times, and initial concentration, which are the factors influencing the removal of U(VI), were investigated. The adsorption of U (VI) onto PEI/GO was fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model. The maximum sorption capacities of U(VI) on PEI/GO (145.14 mg.g(-1)) at pH=7 and T=303 K were higher than that of U(VI) on GO (94.61 mg.g(-1)). This study provides a novel and simple method for synthesizing GO derivatives with efficient adsorption performances of U(VI) from aqueous solution.