this study was carried out to evaluate the in vitro antioxidant activity and the chemical composition of essential oils and organic extracts of moroccan tetraclinis articulata cones (khemisset region). the gc-ms analysis of essential oils identified a total 23 volatile components. the major constituents of the oil were -pinene (18.33%), cis-verbenone (10.02%), and l-pinocarveol (8. 32%). for phytosterols analysis of hexane extract, -sitosterol constitutes the majority with a percentage of 77.74%. the amount of total phenolic and flavonoid contents was high in the methanol extract (78.54+/-2.8 mg gae / g and 41.11+/- 4.5 mg qe/g, respectively) and the antioxidant capacity determined by dpph method showed a strongest radical scavenging activity exhibition by the methanol extract (ic50=0.038+/-0.006 mg/ml). the results indicated that t. articulata contains bioactive compounds which are responsible for its antioxidant activity. therefore, this plant could be potential candidates for the preparation of a natural antioxidant drug or an additive preparation.