Activities of benzo(a)pyrene(BP) metabolizing enzymes and amounts of BP-metabolites were determined in hephatic microsomes of mice treated with two polyacetylene compounds, panaxynol, panaxydol which purified from Korean ginseng root(panax ginseng C.A. Meyer) in order to investigate the effect of polyacetylene compounds on BP-metabolism. As results, two polyacetylenes induced epoxide hydratase(EH) markedly as compared with arylhydrocarbon hydroxylase(AHH). Among BP-metabolites, BP-7,8-diols and BP-quinone compounds increased in hephatic microsome while BP-9,10-diols rather reduced by polyacetylene treatment. In connection with these results, the increment of water soluble BP-metabolites in rat urine and inhibition of total covalent binding between BP-metabolites and DNA in vitro suggest that polyacetylene compounds have a potential to reduce BP induced carcinogenesis.