Chemical compositions of Hung chanh essential oil have been examined by GC-MS Thirty-four compounds were identified, among those the main compounds are: Carvacrol (52.32%), γ-Terpinene (18.92%), p-Cymene (7.56%), Caryophyllene (5.6%), cis-α-Bergamotene (2.86%), α-Humulene (2.68%) and Aromandendrene (1.78%).