采用气相色谱-质谱联用法对重庆野生土荆芥〔Dysphania ambrosioides (Linn.) Mosyakin et Clemants〕果期的果实、叶片、细枝、主茎、根系精油成分进行了鉴定和分析。结果表明：重庆野生土荆芥不同部位精油得率差异明显，果实、叶片的精油含量明显高于细枝、主茎、根系。全株共鉴定出62种成分，果实、叶片、细枝、主茎、根系分别鉴定出24、17、35、31和14种成分，均以单萜烯类成分为主。果实、叶片、细枝中共有成分有13种，其中，α-松油烯、4-蒈烯、对伞花烃含量均较高。主茎和根系精油中成分含量整体均较低，主茎精油中仅α-松油烯和正二十烷的含量高于20 mg·kg^-1；根系精油中仅棕榈酸、正二十一烷、邻苯二甲酸二丁酯、连三甲苯、正二十烷的含量高于2 mg·kg^-1，棕榈酸和邻苯二甲酸二丁酯含量在根系中最高。果实、细枝、主茎、根系中特有成分分别有3、9、11、5种，α-松油烯、驱蛔素仅在果实、叶片、细枝、主茎精油中有检出，对伞花烃仅在果实、叶片、细枝精油中有检出。乙酸香叶酯、植物醇、香叶基香叶醇、α-蒎烯均首次从土荆芥中检出。综上所述，重庆野生土荆芥不同部位精油主要成分组成和含量均存在差异，果实、叶片是精油的主要贮存部位，α-松油烯、4-蒈烯、对伞花烃为主要成分，土荆芥可能通过根系分泌棕榈酸和邻苯二甲酸二丁酯等成分达到入侵目的。

 The components of essential oils from the fruits, leaves, twigs, main stems, and roots of wild Dysphania ambrosioides (Linn.) Mosyakin et Clemants at fruiting stage in Chongqing were identified and analyzed by using gas chromatography-mass spectrometry method. The results show that there are significant differences in yields of essential oils from different parts of wild D. ambrosioides in Chongqing, the essential oil contents of the fruits and leaves are evidently higher than those of the twigs, main stems, and roots. A total of 62 components are identified from the whole plant, and 24, 17, 35, 31, and 14 components are identified from the fruits, leaves, twigs, main stems, and roots respectively, all of which are dominated by monoterpenes. There are 13 common components in fruits, leaves, and twigs, among which, the contents of α-terpinene, 4-carene, and p-cymene are all relatively high. The contents of components in the essential oils of main stems and roots are all relatively low in general, and only the contents of αterpinene and eicosane in the essential oil of main stems are higher than 20 mg·kg^-1; in the essential oil of roots, only the contents of hexadecanoic acid, heneicosane, dibutyl phthalate, 1,2,3-trimethylbenzene, and eicosane are higher than 2 mg·kg^-1, the contents of hexadecanoic acid and dibutyl phthalate are both the highest in roots. There are 3, 9, 11, and 5 unique components in fruits, twigs, main stems, and roots respectively, α-terpinene and ascaridole are only detected in the essential oils of fruits, leaves, twigs, and main stems, and p-cymene is only detected in the essential oils of fruits, leaves, and twigs. Fragranyl acetate, phytol, geranyl geraniol, and α-pinene are all detected in D. ambrosioides for the first time. In conclusion, there are differences in composition and contents of the main components of essential oils from different parts of wild D. ambrosioides in Chongqing, fruits and leaves are the main storage parts of essential oils, α-terpinene, 4-carene, and p-cymene are the main components, and D. ambrosioides may achieve the purpose of invasion by secreting components such as hexadecanoic acid and dibutyl phthalate through the roots.