Objective: To analyze the chemical components of the volatile oil from Aster ageratoides and determine their contents. Method: The volatile oil was extracted from A.ageratoides by steam distillation. Its chemical components were analyzed and identified by GC-MS

and the relative percentage content of each component was calculated by area normalization method. Result: One hundred and twenty-four compounds were isolated from the volatile oil of A. ageratoides and 72 of them were identified

accounting for 67.52% of volatile oil. The major components were caryophyllene oxide (18.38%)

12-oxabicyclo [9.1.0]dodeca-3

7-diene

1

5

5

8-tetramethyl-

[1R-(1R

3E

7E

11R)]-(8.01%)

caryophyllene (3.57%)

n-hexadecanoic acid(4.59%)

humulene (3.16%)

2-pentadecanone

6

10

14-trimethyl (2.51%)

cedrol(2.35%)

cyclohexane

1-ethenyl-1-methyl-2

4-bis(1-methylethenyl)-

[1S-(1(

2β

4β)]-cyclohexane(2.28%)

apiol(1.85%)

(-)-spathulenol (1.32%). Conclusion: The volatile oil from A. ageratoides is mainly consisted of terpenoids

esters

alcohols

aldehydes

hydrocarbons and other chemical components. The analytic results can provided scientific basis for quality control and further exploitation of A.ageratoides.