OBJECTIVE To systematic ally stu dy the chemic al components of ethanol extract from Sanzi san ，and to provide reference for clarifying the pharmacodynamic material basis of the formulation. METHODS HPLC-Q-Exactive-MS technology was adopted. The determination was performed on Shim-pack GIST-HP C 18 column with mobile phase consisted of acetonitrile- 0.1％ formic acid aqueous solution for gradient elution at the flow rate of 1 mL/min. The column temperature was 40 ℃，and sample size was 10 μL. Mass spectrometry conditions included the electrospray spray ion source was used for detection in positive and negative ion detection modes. Full MS/dd-MS 2 detection mode was adopted ，the resolution of Full MS was 70 000 and the resolution of dd-MS2 was 17 500. The scanning range was m/z 110-1 200. The ion peaks were identified by comparing with the information of control substances ，literature references and self-built database. RESULTS A total of 64 components were identified in the ethanol extract of Mongolian medicine Sanzi san ， including 9 flavonoids，13 iridoids，14 organic acids ，18 tannins，3 triterpenes，3 amino acids and 4 fatty acids. CONCLUSIONS The ethanol extract of Mongolian medicine Sanzi san mainly include iridoids ，tannins and flavonoids ，which might be the pharmacodynamic material basis of Sanzi san.