Abstract: ICP-AES was applied to the determination of trace amount of iron in binded ternary cathode material for lithium ion battery. The sample of ternary cathode material (0.200 0 g) was ignited with high temperature to remove carbon and fluorine, and then fused with 2 g of a mixed flux of Na2CO3-H3BO3 (2+1). Matrix matching was adopted in the preparation of working curve. Spectral lines and ion interference were eliminated by selecting wavelength of 233.280 nm as the analytical line for iron and by using background correction. Linear relationship between values of emission intensity and mass fraction of iron was kept in the range within 0.025%, with detection limit (3s) of 0.000 6%. The proposed method was applied to the analysis of substantial samples, giving value of RSD (n=11) of 3.2%. Test for recovery was performed by standard addition method,giving values of recovery in the range of 93.8%-108%.