Several Eucalyptus cultivars has been introduced and cultivated for millions of hectares afforestation in subtropical China, whose woods were mainly used in papermaking industry and whose water essential oils were used mainly in aroma and medical industry. However, the potential biomedical components of organic essential oils were still uncovered. In order to reveal constituent characteristic and biomedical potentials of organic essential oils from leaves of four Eucalyptus cultivars (E. camaldulensis, E. tereticornis, E. citriodora and E. dunnii) in China, their components were efficiently ex...