Essential oil (0.51%) has been isolated from the rhizomes of Zingiber zerumbet from which a white crystalline fraction-A (m.p.620C) has been separated and purified. Another fraction-B (m.p. 660C) has been isolated from petroleum ether (40-600C) extract. The fraction-A & B have been analyzed by, IR, GC/MS. From the above observation it appears that the major constituent of fraction-A & B is same and the structure is possibly 2,6,10- cycloundecatriene-1-one 2,6,9,9- tetramethyl.