Extractions of uranium from thc acidic mcdia, HCI and HNO3 at differcnt concentrations, by the tertiary amines, triiaurylarninc, triisooctyllaminc and trioctylamine wcre systematically investigated. In experiments, 232U was uscd as thc tracer and aliquots of both phases after extractions wcrc taken, ashed at XWC, placed onto stainlcss steel planchcts, and rneasurcd hy a surface-barricr Si(Li) detector connected to an alpha spectrometer.Oncuniquc condition found uscful for complctc scparation ofuranium was that oftheradioactivcuranium present in8 M HC1 bcingcxiractcd with 10% trilaurylamine inqlene. In khat case, greatcr than 95% of the uranium could be cxtracted into the organic solution, whereas vlt of thc radionuclides of a series of its decayed products, "%b, 224Ra, =OR,, 216Po and "'Bi remained completely in the aqueous solution. The same procedure could also be used for the scparation of uranium from a mixture with its activated nuclides. Plutonium239 and 241Am were used as the tracers representing the activated nuclides of uranium. It was found that 241Am was absolutely not extracted, but that 23Pu could be extractcd with >95% efficiency from the medium of 8 M HCI into 10% trilaurylamine in xylcnc. Howcvcr, 23yPv could be easily stripped using the solution mixture of 8 M HC1 and 0.05 M NH4I and cxcludcd from the organic solution.