Abstract: The sorption behaviors of radioactive technetium on stibnite are studied with batch experiment. In order to determine the possible sorption mechanism, dilute sulfuric acid is used to dissolve the technetium adsorbed on stibnite and a series of sorption experiments are carried out under acidic conditions. Both aerobic and anaerobic conditions have been employed, and the results show that a significant sorption of technetium on stibnite is found under aerobic and anaerobic conditions, and the sorption on the mineral is supposed to be due to the reduction of TcO - 4 to insoluble TcO 2· n H 2O. No more than 10 percent of the reduce/sorbed technetium is desorped by dilute sulfuric acid. On addition of H 2O 2 to the leach solution a sudden increase in the technetium concentration is observed. Little or no sorption is found at higher acidity and the sorption ratio increase with the decrease of the concentratin of sulfuric acid.