Abstract: Metallic ions Cu2+,Zn2+,Ni2+,Pb2+ were simultaneously determined by non-suppression ion chromatography (IC) under conditions of a cationic exchanger column,an electric conductance detector and an eluant solution of citrate-ethylenediamine.Effects of eluant composition and pH on the separation are experimentally optimized.Regression equation of the calibration curves for all the four ions are presented,with correlation coefficients in the range of 0.993-0.999,detection limits 0.03-0.10 mg·L-1,RSD′s 1.2%-2.0% and recoveries 98%-106%.The method has been applied to the analysis of waste water.