Hydrous thorium oxide (HTO) was synthesized and laboratory study was conducted to address its applicability for decontamination of barium and strontium ions from radioactive liquid wastes using radiotracer technique. The adsorption of Ba(II) and Sr(II) on HTO has been investigated as a function of pH, concentration and temperature of the adsorptive solution and the results obtained show that these parameters affect the extent of adsorption very appreciably. Pre-treatment of oxide adsorbent with neutrons and γ-radiation from a 11.1 GBq Ra--Be neutron source reduces its adsorption capacity upto 24 hours of irradiation and then enhances it on further irradiation. The nature and mechanism of adsorption are discussed.