In order to develop Cs removal techniques from low level radioactive liquid wastes of decontamination processes, we propose an effective Cs removal method to handle two operations simultaneously at one step, which includes an adsorption of Cs ion from the waste liquors and a flocculation of the adsorbent particles loaded Cs ion. Mixtures of natural zeolite or Prussian blues as cation exchangers, and aluminum sulphate type reagents as flocculants were effective materials. Fundamental study was carried out to remove Cs ions from aqueous solutions using only cation-exchangers, only mineral flocculants, and the mixtures of them.