Abstract: The content of trace alkali metal elements such as Li, Na, K and Cs was determined by ICP-AES. The method uses 3 mol/L nitric acid solution for leaching solution, CL-TBP resin for stationary phase to separate uranium and impurity. The level of impurity in the solution was measured by spectrometer. In this paper, the optimization working parameters of the instrument was introduced, the wavelength of elements was determined and no significant difference between standard curve and working curve was evaluated. The ionization interference of Cs was reduced by the peak-height integral method. The accuracy and validity of this method was verified by different techniques and standard addition recovery. The results show that the relative standard deviations of Li, Na, K and Cs are better than 15%(n=6). The recovery of the method is 90%-110%. While the content of Li is 21.2 μg/g, the relative extended uncertainty （U_rel(Li)） of measured results is 7.2%(K=2).