An adsorption material of carbon-coated iron nanoparticles was synthesized by carbon arc discharge technology. The adsorption and elution behaviors of Cr，Ni，Cd and Pb ions on the above material were studied by inductively coupled plasma-atomic emission spectrometry.The results showed that the studied ions can be adsorbed quantitatively on the above material at pH 8.0-9.0 and the analytes adsorbed on carbon-coated iron nanoparticles can be eluted with acid solutions(pH=1.0-2.0).The detection limits of the method for Cr,Ni,Cd,Pb were 3.6，4.1，1.1,9.8 μg/L，respectively.The calibration curves were linear in the ranges of 1-500 μg/L for Cr，Ni，Cd and 10-1 000 μg/L for Pb，with correlation coefficients more than 0.999.The proposed method was applied in the determination of Cr,Ni,Cd,Pb ions in water sample and the recoveries reached 93%-105%.The adsorption capacities of carbon-coated iron nanoparticles for Cr，Ni，Cd and Pb ions were 3.6，4.8，6.3,2.1 mg/g，respectively.