The essential oil from the fresh leaf of Panax japonicus var.major obtained from Daba mountain was extracted by steam distillation

and the components of the essential oil were separated and structurally identified by GC-MS for the first time

and the relative contents of the components by the peak-area normalization method was adopted in gas chromatography. Seventy-five peaks were separated from the essential oil of the fresh leaf

and 73 components were identified

the major components of the essential oil were β-cubebene (21.39%)

hexadecanoic acid (17.19%)

phytol (5.50%)

phenanthrene (5.05%)

nor-prist-2-one (4.22%)

octadecatrienoic acid (3.35%)

etc. The antimicrobial activities of the essential oil were also investigated. The results of the antimicrobial activities of the essential oil was found to inhibit the growth of testing bacteria and sterilized them especially against Staphylococcus aureus CMCC26112 and Candida albicans CMCC850216.