Objective:To analyze the components of volatile oil from Liquidambar formosana leaves by gas chromatograph-mass spectrometry (GC-MS). Method: The constituents of volatile oil extracted with steam distillation from maple leaves were analyzed by GC-MS. A capillary column DB-5 was used. The column temperature was controlled by a program and the MS analysis was performed with EI and quadrupole mass analyzer. The chemical composition was identified by NIST05 searching and mass spectra comparing and the relative content was calculated by area normalization method. Result: The result showed that 25 compounds which accounted for 92.81% of crude volatile oil were identified. Among the compounds

18 compounds were terpines

5 compounds were aliphatics and 2 compounds were aromatics. The major constituents were α-pinene (34.48%)

β-pinene (19.25%) and limonene (26.97%). Conclusion: The terpines were the major components of the volatile oil

besides pharmacological components. Ten kinds of components of volatile oil were first reported. The result provided a scientific basis for understanding the constituents of volatile oil and further exploitation of Liquidambar formosana leaves.