This study was aimed to determine the chemical composition of essential oils obtained from aerial parts of Thymus algeriensis Boiss. & Reut. and Marrubium vulgare L. collected in the Aures region of Algeria. Essential oils were extracted by steam distillation method and analyzed using GC-MS and GC-FID techniques. Thirty-five (35) and twenty-nine (29) components were identified respectively in T. algeriensis and M. vulgare essential oils to represent respectively 94.8% and 75.7% of the total oil composition. The main compounds of T. algeriensis oil were germacrene D (29.6%), β-caryophyllene (11.0%), E-β-farnesene (7.8%), bicyclogermacrene (4.4%) and δ-cadinene (4.0%), while, β-bisaboene (36.3%), β-caryophyllene (7.8%), phytol (6.2%), nonacosane (4.0%) and heptacosane (3.3%) were the main components of M. vulgare oil. The richness of these two oils in germacrene D and β-bisaboene respectively could suggest a new bioactivity.