Eucalyptus leaves have been used as a common traditional herbal medicine for more than 200 years. In order to further utilize Eucalyptus leaves in biomedicine and put forward new ideas for biomedical manufacturing, the biomedical resources of extractives of Eucalyptus dunnii and Eucalyptus grandis leaves were analyzed by GC/MS. The results showed that: 1) The main constituents of benzene/ethanol extractives in E. dunnii leaves were α-amyrin(9.05%), cyclohexyl-15-crown-5-(6.51%), 1,4,7, 10,13,16-hexaoxanonadecane, 18-propyl-(6.09%), vitamin E (5.83%), 1,19-eicosadiene(5.65%), 1,4-dioxane-2,6-dimethanol(5.32%), coumarin-6-ol, 3,4-dihydro -4,4-dimethyl-7-nitro-(4.42%), 2-furancarboxaldehyde, 5-(hydroxymethyl)- (4.21%), benzene, 1,2,3 -trimethoxy-5-methyl(3.45%), etc. 2) The main constituents of benzene/ethanol extractives in E. grandis leaves were (-)-globulol (7.35%), 1,2,3-benzenetriol(7.17%), D-allose(6.37%), 2- furancarboxaldehyde,5-(hydroxymethyl)-(6.33%), N1-(4-hydroxybutyl)-N3-methylguanidine acetate(5.35%), 1,4,7,10,13,16-hexaoxanonade–cane,18-propyl-(3.95%), vitamin E(3.26%), cyclohexyl-15-crown-5-(3.13%), eucalyptol(2.91%), etc. The results of function analyses suggested that the benzene/ethanol extractives of both E. dunnii and E. grandis leaves were abundant in materials of noble natural biomedicines, and also contained constituents which could be developed into top value-added materials of cosmetics and health care.