the cytotoxic activities of lindera strychnifolia essential oil on nine human cell lines and the induction of apoptosis in hepg2 cells were determined. cytotoxicities of leaf oil were examined on the human carcinoma cell lines (eca-109, hepg2, ht29, mda-mb-231, pc-3, sgc7901, sw1990 and u2-os) and a normal cell line (hl-7702) using the mtt assay. apoptotic effects of leaf oil on hepg2 cells were investigated using hoechst 33258 staining, agarose gel electrophoresis and flow cytometry. also, cytotoxicities of four compounds from the essential oil were studied. our results showed that leaf essential oil exhibited significant cytotoxicity against all the cells tested with a potential selectivity for cancerous cells. the lowest ic50 of 22.68+/-1.19 g/ml was measured for hepg2. the anticancer mechanism of leaf essential oil on hepg2 cells involved induction of apoptosis. also, geraniol and bornyl acetate exhibited some cytotoxicity. the data suggest that leaf essential oil of l. strychnifolia could be a potential medicinal resource in cancer therapy.