Artemisia campestris locally named “T’gouft” which belongs to family of Asteraceae, is known to have anti-inflammatory, antioxidant, antimicrobial and many other bioactivities. The objective of this study was to evaluate antioxidant activity of Artemisia campestris from two regions of Algeria (Bousaada and Oum El Bouaghi). A. campestris extracts were prepared with different polarity solvents (water and methanol) and analyzed using different tests in vitro in order to evaluate their antioxidant activity and phenolic content. Total phenolic, flavonoid and tanin contents were evaluated, and three tests were established to assess the antioxidant activity. Total phenolic of the samples was analyzed using Folin – Ciocalteu methods; it was expressed as mg gallic acid/g of extract, and the content varied from 7.47 to 88.61 mg/g of extract. Flavonoid of the samples was detected using aluminum chloride, expressed as mgquercetin/ g of extract, and the content varied from 12.91 to 33.14 mg QE/g extract. The antioxidant activity of A. campestris was evaluated using three complementary test systems: DPPH scavenging, FRAP andβ-carotene-linoleic acid respectively. The IC50 values for DPPH were ranged from 48 to 241 µg/ml. The EC50 values in FRAP assay were ranged from 266 to 871µg/ml while in β-carotene-linoleic acid assay, good inhibition was found in the methanolic extract.