A 0.23% (v/w) extract was obtained from the whole plant of A. przewalskii. The extract was pale-green with an aromatic-spicy odor. Forty-two components were identified in the oil of A. przewalskii, which represented 96.38% of the total composition of the oil. Sesquiterpene hydrocarbons (7.10%) and monoterpene hydrocarbons (50.85%) dominated the leaf oil composition. 1,8-Cineole (25.99%), camphene (21.05%), -pinene (10.56%), p-cymene (5.59%), and -pinene (4.63%) are major constituents in the essential oil. To the best of our knowledge, the essential oil compositions of A. przewalskii from China have been rarely analyzed in the previous work. The present result has shown that the oil is rich in monoterpenes, but the content of monoterpenes is exceptionally low in our case. The essential oils of A. przewalskii are a prospective source of interesting natural compounds. A biological activity study of the essential oils of Stachys species showed that the plant has antibacterial, antifungal, and antioxidative activity, which can be related to the essential oil composition. Oils rich in 1,8-cineole are known for their antibiotic, insecticide, and antifebrile properties. At the same time, they have good transdermal permeation. To provide a basis for the development of a new dosage form, we need to pursue studies on the pharmacology of the essential oil. SPSS 17.0 statistical software was used to calculate the average inhibition zone diameter. The final result indicated that the essential oil of A. przewalskii has no inhibitory effect on Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Aspergillus niger but has different degrees of inhibitory effect for the other strains. The antibacterial activity strength is: Staphylococcus aureus > Streptococcus hemolyticus- > Micrococcus luteus > Bacillus subtilis > Escherichia coli > Salmonella paratyphy B. In summary, it is concluded that the essential oil of A. przewalskii might be useful against Staphylococcus aureus bacteria. Our further research will focus on the therapeutic application. Plant Material. The whole plants of A. przewalskii were collected in Qinghai Province in October of 2011. The plant was identified by P. C. Lin, and a voucher specimen was deposited in the herbarium of the Botanical Garden in Gansu. Distillation. The fresh plants were chopped and hydrodistilled using a Clavenger apparatus. The oil was dried with anhydrous sodium sulfate to remove moisture. The fraction was obtained and stored at 4C until use.