In this study,UPLC-Q-Orbitrap HRMS was used to analyze the secondary metabolites of E. ulmoides leaves between arboreal forest and leaf forest.The differences of them were analyzed and compared.Accurate qualitative analysis was carried out by combining multi-level ion fragment information with mzCloud network database,high resolution mass spectrometry database of traditional Chinese medicine,comparison of reference materials and literature database.A total of 62 species of secondary metabolites were identified,including 9 flavonoids,9 phenylpropanoids,2 iridoids,21 organic acids,5 coumarins and 16 other components,among which coumarins were first discovered in E. ulmoides leaves.Principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA)were used to process the sample data.The results showed that E. ulmoides leaves of arboreal forest could be distinguished from E. ulmoides leaves of leaf.According to VIP value >1,10 components with different relative contents were screened from E. ulmoides leaves.The components with significant differences (P<0.05) were D-(-)-quinic acid,citric acid,4-methylumbellione,4,5-dicaffeylquinic acid,3′,4′ -dihydroxyphenylacetone by independent sample t-test.This method can accurately and efficiently determine the chemical constituents in eucommia ulmoides leaves and analyze the changes of their relative content,which provides a theoretical basis for quality evaluation of eucommia ulmoides leaves.

"> Eucommia ulmoides leaves of arboreal forest, E. ulmoides leaves of leaf forest, secondary metabolites, UPLC-Q-Orbitrap HRMS, chemical pattern recognition