To report simultaneous determination of copper, zinc and iron in serum by micro-computerized polarography with the system of ethylenediamine-triethanolamine[H 2NCH 2CH 2NH 2-N(CH 2CH 2OH) 3], and assay the concentrations of copper, zinc and iron in serum from 758 healthy subjects.For copper, zinc, iron,with same linearty of range 0~4 g/L, the detection limits were 7.8×10 -5 g/L、5.9×10 -5 g/L,and 8.2×10 -6 g/L, the SD(CV) of sample analysis is 0.05(4.56%),0.05(4.59%), and 0.06(4.51%)...