Volatile oil was extraeted from Folium Artemisiae Argyi by using steam distillation with extracting efficiency of 0.65%. The oil was emulsified by 1% Twain 80. The emulsion stability was good, safe and feasible. In vitro antibacterial experiment results demonstrated that volatile oil from Folium Artemisiae Argyi had best inhibition effect against Bacillus anthracis, the second strongest effect against Staphylococcus aureus and Escherichia coli, but had no obvious inhibition against Pasteurella, Streptococcus and Salmonella.Volatile oil from Folium Artemisiae Argyi had antimierobial activities ...