Abstract: In order to develop a fast and reliable procedure for analysis of transuranium elements in environmental samples, the performance of UTEVA extraction chromatography in separation of transuranium elements is studied. The separation experiment parameters are optimized in terms of the conditions for Pu and Np oxidation state adjustment and control, and the eluent composition and concentration for each of these four elements. The separation efficacy is evaluated. It is found that Am, Pu, Np, and U are effectively eluted from the column by 3 mol/L HNO₃, 1 mol/L HNO_3-0.1 mol/L ascorbic acid, 2 mol/L HCl-0.1 mol/L oxalic acid, and 0.01 mol/L HNO₃, respectively. The recoveries (93±1)%, (68±2)%, (44±3)%, and (70±5)% are respectively obtained (n=6). The mutual decontamination factors fall in the range 1×10² - 5×10⁵. Our results demonstrate that the separation of Am, Pu, Np, and U with a single UTEVA extraction chromatographic column is achievable. The method has been successfully applied to separation of these elements in environmental samples.