Abstract: The essential oils of the aerial parts of two populations of Moricandia arvensis in the Setif region (Algeria) were analyzed by gas chromatography and mass spectrometry (GC-MS). Thirty compounds were identified from the oils of M. arvensis, representing 80.8% of the total essential oil of southern population and 19 compounds of the population north of Setif, representing 93% of total oil. The analysis showed that the essential oils are rich in fatty acid (34.1-22.1%). The major constituent are palmitic acid (13.2-12.9%) and the phytol (7.9-10.5%). The Setif population is characterized by 3-butenylisothiocyanate and Octadecanoic acid, 2-hydroxy-1,3-p. The effects of these oils on the growth of Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923) were investigated by the diffusion method. The oils showed no significant antibacterial activity.