The component of essential oil from Artemisia annua L. was investigated and both hexanal and l-α-pinene were isolated as a low boiling point component. Benzylalcohol acetate, d-2-methyl butyrate, cuminal, caryophyllene oxide, and pentacosane were isolated as a high boiling point component. Besides that, aldehyde compound (semicarbazone, m.p. 200°, 2, 4-dinitrophenylhydrazone, m.p. 157-159°) of C₁₀H₁₆O, and ketonic derivative (2, 4-dinitrophenylhydrazone, m.p. 181-183°) of C₁₅H₂₄O have been isolated and also a presence of monoterpene alcohol derivative bp₅ 90-95°, as well as the sesquiterpene alcohol derivative of bp₅ 134-140°, have been suggested, though their identification have not yet been made.