Abstract: Uranyl species sorbed on cation exchanger from H2SO4 and HCl solution are thoroughly studied by IR spectra and equivalent accounting. The spectra are recorded with DIGILAB FTS-15C infrared spectrometer. The assymetric stretch, v3 of the uranyl group is infrared active. UO2 2+ and (UO2HSO4)+ from H2SO4 solution and UO2 2+ and (UO2Cl)+ from HC1 solution are found to be sorbed on the cation resin. The species sorbed on cation exchanger shows only a single band at 945.3cm-1. or 949.2cm-1 when the equilibrium is carried out in the solution with very low concentration of H2SO4 or HC1 respectively. The species should be UO2 2+. However, a new band at 902.9cm-1 or 906.6 cm-1 is found when the equilibrium is carried out in the solution with high concentration of H2SO4 or HC1 respectively. With increasing the acidity of the equilibrium solution the gradual increase of intensity of the new band and the gradual decrease of intensity of the original one can be observed. As a cation exchanger selectively sorbs cation, the species now sorbed should be either (UO2HSO4)+ or (UO2Cl)+. But the amount of (UO2HSO4)+ or (UO2Cl)+ on the cation exchanger can be ignored with a concentration of acids less than 0.5 N, The equivalent accounting method is applied to the resin loaded with uranyl ion and hydrogen ion, together with cation uranyl complex species, under the conditions of negligible invasion of uarnyl species. A known amount of resin in hydrogen form is equilibrated in a batch process with a solution containing uranyl and sulfuric acid(or hydrochloric acid) at various ratios. It is found experimentally that the amount of (UO2HSO4)+ or (UO2Cl)+ sorbed on exchanger is so low that they can not be observed by the method within experimental errors.It may be concluded that the (UO2HSO4)+ or (UO2 Cl)+ sorbed on cation exchanger can be overlooked under the general conditions of the experiment.