Abstract: A method of chromatographic adsorption accompanied with complex-formation was developed for purifying rare earth salts from heavy metal impurities. This method provides a means to remove the following heavy metal impurities from rare earth salts to an extent of ppm level: Fe<0.57, Cu<0.5, Co<0.2, Ni<1.0 and Pb<0.2, by simply passing the solution through a chromatographic column made up of blended active charcoal and complexing agent. This method enables purification to be accomplished with a higher efficiency and in a larger capacity than other methods. The efficiency of different complexing agents and the optimum conditions have been studied. A possible reaction mechanism in the chromatographic column has been suggested as follows: 1/3Fe³⁺ (ι) + QH(s) = QFe_1/3 (s)+H+(ι).