Abstract: The concentration and separation of Np and Pu in TRPO process are studied by anion exchange method. Oxalic complex ions of Np and Pu in suitable H 2C 2O 4 HNO 3 solution are absorbed by an anion exchange column, then they are eluted by 0 35 mol/L HNO 3. The eluated solution is adjusted to 8 mol/L HNO 3 and is absorbed as nitrate complex by another anion exchange column. Pu and Np on the column are eluted by 5.6 mol/L HNO 3 0.05 mol/L Fe(NH 2SO 3) 2 and 0 35 mol/L HNO 3, respectively. The concentration and separation process of Np and Pu are given out. Np and Pu are concentrated 840 times in the process, separation coefficient is β Pu/Np >100 and β Np/Pu >300, recovery of Np and Pu is 97.6 % and 97.4 %, respectively.