The simple and effective method for determination of gross alpha activities of Pu and Am in environmental and concrete samples was developed. Pu and Am in the sample solution were simultaneously separated from interference elements with extraction chromatography using an Eichrom TRU. SpecTM resin column. After separation, gross alpha activities of these elements on NdF3micro precipitation were simultaneously measured by ZnS (Ag) scintillation counter. The chemical recoveries of these elements were quantitative. The interference of natural alpha emitter could not be found from the results. The advantage of the present method is quantitative recoveries of these elements and effective purification from natural alpha emitters (Th and U) . Furthermore, the present method reduces the time and cost for sample separation.