Abstract: The sample of diesel antiwear agent (0.500 0 g) was dissolved with 10 mL of toluene, and then diluted to 30 g with toluene. ICP-AES was applied to the determination of trace amounts of 11 elements, i.e. Na、K、Ca、Mg、Fe、Mo、Zn、P、B、Si and Sn in the sample solution. Oxygen flow was 30 mL·min^-1. Analytical spectral lines of 588.957 0, 766.444 0, 393.386 0, 279.512 1, 259.913 0, 202.016 7, 213.815 8, 214.915 7, 249.713 5, 251.613 4, 189.917 7 nm were chosen for the determination of Na、K、Ca、Mg、Fe、Mo、Zn、P、B、Si and Sn respectively. The deposition of carbon could be avoided effectively by introducing oxygen to plasma. Y was used as internal standard. Linearity ranges of the 11 elements were found in the same range of 0.05-10.0mg·L^-1 with detection limits (3s) in the range of 0.001 2-0.086 1 mg·kg^-1. Tests for recovery were made by standard addition method at the concentration level of 1.000 mg·kg^-1, giving values of recovery and RSD's (n=6) in the ranges of 95.7%-107% and 1.3%-4.7% respectively.