Leaves and flowers of Inula viscosa (L.) were collected from fields in Kafr Hoor village in western south of Syria. Essential oil was isolated by classical method of steam distillation using the Clevenger-type apparatus. Its chemical composition was analyzed by GC/MS. The analysis figured out the identification of 51 components in aerial parts. Major components of Essential oils were characterized by Sesquiterpens, Phenols, Hydrocarbons, Monoterpenes, Aldehyde & Ketones, Diterpene , Alcohol , Tetraterpene with percentage amounted to about 23.8 % 8.8 % 7.8% ,7.3 % , 5.8 % 5.2 % 4.5 % , 2.1 % respectively .