ObjectiveA rapid method for identification of chemical constituents in Baoyuantang reference sample was established in order to clarify the material basis of this formula. MethodBased on ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS） and self-established database information， the chemical components in Baoyuantang were systematically characterized and identified. The chromatography was performed on a Waters ACQUITY UPLC HSS T3 column（2.1 mm×100 mm， 1.8 μm） with mobile phase of 0.1% formic acid aqueous solution（A）-0.1% formic acid acetonitrile solution（B） for gradient elution（0-3 min， 2%-19%B； 3-8 min， 19%B； 8-8.1 min， 19%-22%B； 8.1-14 min， 22%-29%B； 14-16 min， 29%B； 16-32 min， 29%-45%B； 32-32.1 min， 45%-90%B； 32.1-35 min， 90%-95%B； 35-36 min， 95%-98%B； 36-37 min， 98%-2%B； 37-40 min， 2%B）. Based on electrospray ionization（ESI）， continuum data format was collected in both positive and negative ion modes with a scanning range of m/z 50-1 500. Chemical constituents in the decoction of Baoyuantang were systematically analyzed by UNIFI 1.9.4 software matching， control comparison， The Encyclopedia of Traditional Chinese Medicine（ETCM） database search and literature reports. ResultA total of 229 components were identified under negative ion mode and 181 under positive ion mode， with a total of 322 components after removing duplicates， including 116 triterpene saponins， 66 flavonoids， 19 organic acids， 6 gingerphenols， 6 gingerols， 5 gingerones， 10 amino acids， 7 saccharides， 5 coumarins and 82 other components. Among them， 83， 141， 39， 35 and 38 components were attributed to Ginseng Radix et Rhizoma， Glycyrrhizae Radix et Rhizoma， Astragali Radix， Cinnamomi Cortex and Zingiberis Rhizoma Recens， respectively. ConclusionIn this study， the rapid characterization and identification of multi-class components in Baoyuantang was realized， and it was confirmed that the material basis of this formula was mainly triterpenoid saponins， flavonoids， gingerols and organic acids， and the chemical composition was attributed and analyzed， which provided a reference for the subsequent quality control research.