Development of novel methods of the radiochemical analysis for natural and artificial radionuclides is one of the most urgent current tasks. This work deals with studying of laws of sorption pre/concentration of strontium and radium radionuclides in dynamic conditions with the use of the Dowex Marathon HC, T-3K and T-5 sorbents. Methods. We have conducted a number of experiments on sorption of alkaline earth elements from natural water. We measured the elements concentration with the mass-spectrometry method and used Ra-223 radioactive isotope to study the radium sorption. Results. The results of column tests using a natural spring water showed that the T-3K sorbent provided the best selectivity of strontium sorption over other alkaline earth ions; thus it could be recommended for Sr-90 pre/concentration in radio/ analytical applications. The T-5 sorbent provided the highest selectivity for barium making it prospective for radium pre/concentration; the experiments on radium sorption from Ra-spiked natural water confirmed high effectiveness of this sorbent. Repeatability of barium sorption by the T-5 sorbent was shown using 18 samples of water from different springs.