Abstract: OBJECTIVE To identify the chemical constituents of Xiao'er Qingyan granules by using UPLC-Q-TOF-MS technology.METHODS The separation was performed on a Phenomenex Kinetex XB C₁₈ column(2.1 mm×150 mm, 1.7 μm) with mobile phase of water(containing 0.1% formic acid)-acetonitrile with gradient elution at a flow rate of 0.25 mL·min^-1. Electrospray ion(ESI) source was applied to collect multi-level mass spectrometry fragment information under positive and negative ion modes. RESULTS A total of 59 chemical constituents were identified by high mass spectrometry data analysis, literature comparison and reference confirmation. The chemical constituent cluster was composed of 5 iridoids, 15 organic acids, 5 chromones, 14 flavonoids, 4 lignans, 9 phenylethanoid glycosides, 2 nucleosides, 2 phenols and 3 other compounds. Furthermore, all of the constituents were surveyed and classified according to their medicinal materials derivation. CONCLUSION The proposed method is sensitive and efficient, and can be applied in identification analysis of various chemical constituents of Xiao'er Qingyan granules, which provides a crucial basis for further studying the material of Xiao'er Qingyan granules' efficacy and mechanism.