The europium sorption on Tamusu clay was investigated by batch sorption experiments and spectroscopicstudy under the condition of strong ionic strength. The results demonstrated that europiumsorption on Tamusu clay increased rapidly with pH value, but decreased with the ionic strength of solutionincreased. The europium sorption also increased in the presence of humic acid, especially at lowpH value. The sorption could be fitted by Freundlich isotherm model and the europium sorption on claywas spontaneous and endothermic reaction. Besides, the result indicates that ion exchange was the mainprocess at low pH value, while inner-sphere surface complexation dominated the sorption process athigh pH value. The Backscatter electron scanning/Energy Dispersive Spectrometer(BSE/EDS) and theeffect of Na for europium sorption results further suggested that europium sorption on Tamusu claymainly competed with Na at low pH value. Overall, the results in this research were of significance tounderstand the sorption behavior of europium on the geological media under high ionic strength.