Abstract: Three geranium oils were separated, identified and compared by high resolution cross-linked fused silica capillary GC and GC-MSD. It was found that their chemical constituents are very similar, but the contents of some components (linalool, citronellol, cis-caryophyllene and guaiene) differ appreciably.Pharmacological experiments showed that citronellol, citrenellyl formate, geraniol and citronellyl acetate exhibited marginal antitumour activities. The activity of the latter two components has not been reported in the literature.