ObjectiveTo establish a qualitative and quantitative analysis method for chemical constituents in Liu Junzitang（LJZT）， and to clarify its material basis. MethodThe chemical constituents in LJZT were analyzed by ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS）， and the resulting compounds were identified by using databases， such as MassBank， PubChem， ChemSpider， Traditional Chinese Medicine Systems Pharmacology Database and Analytical Platform（TCMSP）， and by combining with relevant literature. UPLC was used to establish a quantitative method for analysis of 9 compounds in LJZT， including liquiritin， hesperidin， lobetyolin， liquiritigenin， glycyrrhizic acid， nobiletin， tangeretin， atractylenolide Ⅱ and Ⅰ. ResultBy combining the relevant literature， database and MS information， a total of 79 compounds were identified from LJZT， including 31 flavonoids， 15 terpenoids， 14 nitrogen-containing compounds， 6 phenylpropanoids， 6 organic acids and 7 other compounds. The established quantitative analytical method for the nine representative components showed good linearity within their respective linear ranges， and the precision， stability， reproducibility and recovery were in accordance with the requirements. The quantitative results showed that the contents of liquiritin， hesperidin， lobetyolin， liquiritigenin， glycyrrhizic acid， nobiletin， tangeretin， atractylenolide Ⅱ and Ⅰ in LJZT were 0.376 5， 2.602 1， 0.082 6， 0.128 1， 1.778 6， 0.015 7， 0.006 7， 0.030 4， 0.003 2 mg·g^-1， respectively. ConclusionThe established method can quickly， sensitively and accurately analyze the chemical constituents in LJZT， clarify that the material basis of LJZT is mainly flavonoids， terpenoids and nitrogen-containing compounds， and simultaneously determine the contents of the 9 components， which can lay a foundation for the research on quality control， mechanism and clinical application of LJZT.