Abstract: OBJECTIVE   To establish a qualitative analysis method of xanthones in Swertia chirayita by ultra-high performance liquid chromatography-time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS).METHODS   Acquity HSS T₃ column (100 mm×2.1 mm, 1.8 μm) was used as the chromatographic column, with 0.1% formic acid in water-0.1% formic acid in acetonitrile as the mobile phase for gradient elution.The volume flow rate was 0.4 mL·min^-1 and the column temperature was 40 ℃.In the positive and negative ion modes, the mass spectrum data of Swertia chirayita was collected and identified by Masslynx4.1 software combined with SciFinder database, comparison with mass spectrometry data analysis, reference materials and reference to relevant literatures.RESULTS   A total of 25 xanthone compounds were identified, 3 of which were first discovered including 7-O-β-D-xylopyranosyl-1, 8-dihydroxy-3-methoxyxanthone, swerpunilactone B and 8-O-β-D-xylopyranose(1→6)-β-D-glucopyranose-1, 7-dihydroxy-3-methoxyxanthone.CONCLUSION   The method can provide an experimental basis for the qualitative analysis of xanthones and the quality control of medicinal materials in Swertia chirayita.