Abstract: The sample of licorice root was digested with HNO3 and H2O2 in the Mars microwave digestor and 6 kinds of trace elements (i.e., Ni, Pb, Cr, Cd, As and Se) in the solution were determined by ICP-MS. The spectral in terferences of polyatomic ions were eliminated by the use of dynamic reaction cell (DRC). Under the optimized conditions, values of detection limit (3s) of the method found were in the range of 0.013-0.12 μg·L-1. In the analysis of a CRM of shrubs branches and leaves by the proposed method, the results obtained were in consistency with the certified values.