Abstract: The essential oil of the liverwort Lophozia ventricosa was analyzed by GC and GC - MS. 28 constituents were identified, comprising 93.3% of the oil. 1 monoterpene (α-pinene), 23 sesquiterpenes (15 of them are oxygenated) and a diterpene (fusicoccadiene) are presented in the oil. A nor-sesquiterpene hydrocarbon ventricos-7 ( 13 ) -ene with a new skeleton is also detected. The major constituents in the oil are maalioxide (45.6%) and eudesma-4 (15), 7 (11)-dien-8-one (28.9%). Fig 2, Tab 1, Ref12