ObJective: To study the chemical constituents and antioxidant activity of the essential oils from Cinnamomum burmannii in Guangxi. Method: The essential oils were extracted by steam distillation

and then the constituents were separated and identified by GC-MS. The scavenging activities on DPPH radical

ABTS+radical and reducing power were detected by UV-Vis spectrophotometry. Result: 137 compounds were isolated and 61 compounds were identified in the leaves that composed about 93.58% of the total essential oils. The maximal scavenging rate on DPPH and ABTS+ radical reached to 21.71% and 58.89%

respectively. And these oils had weaker reductive capability than BHT. Conclusion: The principal chemical constituents of the essential oils are caryophyllene (21.71%)

eucalyptol (18.22%)

guaiol (7.52%)

(+)-α-terpineol (7.06%)

(-)-β-pinene (3.57%)

γ-eudesmol (3.33%)

bulnesol (3.16%)

(Z)-nerolidol (3.16%)

elemol (2.67%)

α-caryophyllene (2.22%)

(1S)-α-pinene (1.9%)

(-)-terpinen-4-ol (1.8%)

(+)-ledene (1.35%)

caryophyllene oxide (1.29%)

and γ-terpinen (1.05%). These oils possessed good scavenging activities on ABTS+ radical

but showed low activities on scavenging DPPH radical and reducing power. And the antioxidant activities of these oils were concentration-dependent.