Abstract: Volatile oils were extracted from two Artemisia species of Yan’an by steam distillation. Antifungal and antibacteria activities were measured by mycelium growth rate and 96 well plate method. The results showed that at the concentration of 2.0 mg/mL, the antifungal activity of Artemisia stelleriana oil was weak and the highest inhibition rate was only 57.3% against Sclerotinia sclerotioru. Volatile oil of Herba artimisiae sieversianae showed significant antifungal activity against 9 tested fungus and inhibition rates reached above 90% against Cylindrocarpon destructans, Venturia nashicola, Alternaria alternata. Antibacterial activities of the oils were not observed except for Escherichia coli and inhibition rates were 500 mg/mL. Chemical components of volatile oils were analyzed and determined by gas chromatography- mass spectrum. 26 compounds were indentified from A. carvifolia oil. The most content was caryophyllene oxide and the content reached 25.75%. 49 compounds were indentified from H. artimisiae sieversianae and the highest contest of penylene pentane was 30.37%. The result showed volatile oil of H. artimisiae sieversianae had potential to be developed as new type green fungicide agents.