Abstract: The determination of Na~+ and K~+ ions in the high-level liquid waste is investigated using ion chromatography, In order to protect the low capacity ion exchange resin in single column IC and remove the transition metal as well as other heavy metal ions that are contained in liquid waste, the pretreatment column with EDTA chelating resin is used. Those impurity metal ions are strongly absorbed by EDTA chelating resin and 100% of Na~+ and K~+ ions in the solution are eluated. The ability of the decontamination of EDTA chelating resin is satisfactory. The sample of the high-level liquid waste is dilluted appropriately, then an aliquot of the sample is passed through the pretreatment column with EDTA chelating resin, the eluate is analysed by single column ion chromatography. The precision of this method is better than 5% for the determination of Na~+ and K~+ ions (at μg·ml~(-1)level)