Abstract: The separation and determination method of 233 Pa and 237 Np is studied. 233 Pa is quantitatively adsorbed by Vycor glass column from 8 mol/L HNO 3 solution containing 237 Np 233 Pa. Subsequently, 233 Pa is eluted from the Vycor glass column with concentrated H 2SO 4 solutiion and Np and Pa is completely separated. Then α radioactivity of 237 Np and γ radioactivity of 233 Pa are measured with liquid scintillation counting method and γ energy spectrum method separately. The precision of the method is: 2 % for 237 Np, 3 % for 233 Pa, the recovery of added standard radioactive samples is: 99 %～101 % for 237 Np, 99 %～103 % for 233 Pa.