Amine containing polymers (ACPs) were synthesized by heating glyoxal and melamine under argon conditions. The batch characterization, including SEM, FTIR, XRD and XPS techniques, indicated that ACPs had various nitrogen-containing functional groups. The batch experiments indicated that ACPs presented the high removal performances (Qmax = 250 mg/g, calculated by Langmuir model), well stability, strong salt tolerance and great regeneration cycle toward U(VI). XPS analysis confirmed the coordination of U(VI) with nitrogen- or oxygen-containing groups via covalent bonding. The theoretical calculations revealed that the binding energies of U-N, U-O and U-C were -27.49, -16.94 and -11.81 kcal/mol, respectively, indicating that U(VI) was tended to combine with nitrogen- containing groups. These observations suggested that ACPs can be regarded as a promising adsorbent for immobilization and pre-concentration of U(VI)-containing wastewater in environmental cleanup.