Both essential oils of fresh and air-dried Asarum caulescene (Maxim.) were analyzed by GC-MS in three different polarities. The results show that thirty-four components were identified in the oils, and main compounds of both oils were β-pinene (7.63% vs. 20.72%), 2-carene (8.94% vs. 7.99%), β-phellandrene (7.80% vs. 14.39%), 1,8-cineole (8.91% vs. 13.29%) and germacrone (46.64% vs. 6.64% ), however, the content of monoterpene hydrocarbons(30.29% vs. 52.30% ) and oxygenated sesquiterpenes( 47.69% vs. 10.65%) of both oils was different. The antimicrobial activity of the oil was evaluated against 3 fungi and 11 bacteria including 7 clinical isolated strains. Our results showed that both oils presented a broad antimicrobial spectrum, and compared with the essential oil from fresh herb, the extracted oil from dried herb had better antimicrobial activity, its minimum inhibitory concentration(c_ mi ) values of dried herb were 0.16-2.5 g/L and lowest minimum bactericidal concentration(c_ mb ) value was 0.31 g/L. Both essential oils of fresh and air-dried Asarum caulescene (Maxim.) were analyzed by GC-MS in three different polarities. The results show that thirty-four components were identified in the oils, and main compounds of both oils were β-pinene (7.63% vs. 20.72%), 2-carene (8.94% vs. 7.99%), β-phellandrene (7.80% vs. 14.39%), 1,8-cineole (8.91% vs. 13.29%), and germacrone (46.64 % vs. 6.64% ), however, the content of monoterpene hydrocarbons (30.29% vs. 52.30% ) and oxygenated sesquiterpenes ( 47.69% vs. 10.65%) of both oils was different. The antimicrobial activity of the oil was evaluated against 3 fungi And 11 brace including 7 clinical isolated strains. Our results showed that both oils presented a broad antimicrobial spectrum, and compared with the essential oil from fresh herb, the extracted oil from dried herb had better antimicrobial activity, its minimum inhibitory concentration(c_ mi ) Values ​​of dried herb were 0.16-2.5 g/L and lowest minimum bactericidal concentration(c_ mb ) value was 0.31 g/L.