Abstract: In 5 cm diameter electrolytic reduction pulsed columns using a dispersed system of uranyl nitrate in 30 volume percent tributyl phosphate and nitrite acid solution containing hydrazine, the behaviors of uranium ( Ⅵ ) electrochemical reduction are extensively investigated under different process conditions. The results obtained for uranium are proved that there is obvious influene of such basic variables as cathode potential, flow rates, U (Ⅵ) concentrations, temperature, ratios of cathode to anode surface aera and characteristic geometry ceeficients ( π = S/V ) on the uranium reduction efficiency. The concentration profiles of U (Ⅳ), HNO_3 and N_2H_5NO_3 are predictively suitable for separation of pluto-nium from uranium. Experiments show that the gases produced in a considerablly smaller volume rate at eletrodes. The contents of hydrogen and hydrazoie acid are far below the safety limit. The concen-trations of U(Ⅳ) to meet the U/Pu separation can be achieved conveniently by varying some parame ters.