Abstract: For comprehensively understanding of the chemical composition in Xueshuan Xinmaining Tablet（XXT）, ultra high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF MS) was developed. The automated data processing software UNIFI was selected to perform the screening analysis on the structural characteristics and MS fragmentation behavior, especially for characteristic fragments. Separation was performed on a Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm×1.7 μm) at 40 ℃. The mobile phase was consisted of 0.1% formic acid aqueous solution (A) and 0.1% formic acid in acetonitrile (B) with the flow rate of 0.4 mL/min. The data were collected with Masslynx V4.1 workstation. The MS raw data were processed using the streamlined workflow of UNIFI software to quickly identify the chemical components that met the match criteria with the in-house Traditional Medicine Library and the self-built database. The self-built database of compounds, such as saponins, flavonoids, volatile oil, amino acids and so on, was established by searching online databases such as China Journals of Full-Text Database (CNKI), PubMed, Medline, Web of Science and ChemSpider. By comparing the exact molecular mass, retention time, and mass spectrometry fragment ion information of each component, a total of 187 chemical constituents are identified, including triterpenoid saponins, phenanthrenes, oxadienes, steroids and other structural types of compound. This method is rapid and comprehensive for analysis of the chemical constituents of complicated herbal extracts. XXT is rich in small chemical components with various structural types. The study offers the pharmacodynamic basis for antithrombus effect and multi-target mechanism of XXT.