80CHEMICAL AND ANTIMICROBIAL PROPERTIES OF ESSENTIAL OILS OF Olea europea LThe analysis and identification of components of the essential oil of Olea europea leaves were performed using the (GC-MS). The yield of essential oil samples is 0.01%.This analysis led to the identification of 38 compounds representing 94.1% of the total oil. The chemical composition of the essential oil is dominated by the products, palmetic acid (14.71%), Znerolidol (9.45%), octacosane (6.32%), caryophyllene oxide (4.77%), tetracosane (4.06%) and the 4-hydroxy-4-methyl-2- Pentanone (4.04%). The essential oil has a very effective antibacterial activity against bacterial strains Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC27853 and Citrobacter freundii ATCC 8090, while it has no significant antibacterial activity against Escherichia coli ATCC 25922 and Bacillus subtilis ATCC 6633.tlograda63@yahoo.frResearch512015Oleaeuropea L,Essential oil,Chemical composition,Antibacterial Activity,AlgeriaHabiba Boukhebti,Adel Nadjib Chaker,Takia Lograda,Messaoud RamdaniLaboratory of Natural Resource Valorisation, SNV Faculty, Setif 1 University, 19000 Setif, Algeria.,Laboratory of Natural Resource Valorisation, SNV Faculty, Setif 1 University, 19000 Setif, Algeria.,Laboratory of Natural Resource Valorisation, SNV Faculty, Setif 1 University, 19000 Setif, Algeria.,Laboratory of Natural Resource Valorisation, SNV Faculty, Setif 1 University, 19000 Setif, Algeria.