Based on the preparation and purification of Np(Ⅴ), the extraction behavior of Np(V) is studiedunder various initial conditions. These initial conditions are as follows: one is that the TBP/OK is treatedor is not treated by KMnO_4 oxidation and the sodium nitrite is used as stabilizing agent, the other is thatthe TBP/OK is treated by KMnO_4 oxidation and the urea is sued as stabilizing agent. Under these initial The initial conditions are as follows: one is that the TBP / OK is treatedor is not treated by KMnO_4 oxidation and the sodium nitrite is used as stabilizing agent, the other is that the TBP / OK is treated by KMnO_4 oxidation and the urea is sued as stabilizing agent. Under these initial