During the investigation on the constituents of liverworts, (-)-ent-spathulenol and (-)-ent-bicyclogermacrene were frequently found in many species. While studying the liverwort Dicranolejeunea yoshinagana, it was observed by chance that (-)-ent-bicyclogermacrene is easily converted to (-)-ent-spathulenol. A pure sample of (-)-ent-bicyclogermacrene was allowed to stand at room temperature and was found to have changed completely to (-)-ent-spathulenol. The conversion was accomplished quantitatively and the enantiomeric purity of (-)-ent-spathulenol was equivalent to that of (-)-ent-bicyclogermacrene. This transformation also occurred during the extraction of liverworts.