en پژوهشي Research Article Recent investigations have shown that plants have antioxidant properties and could decrease oxidative stress in different human diseases. The present work was identified the chemical composition compounds and evaluated the various antoxidative activities of Ferula-assa-foetida leaves hydroalcoholic extract (FLHE) and Ferula-assa-foetida leaves essential oil (FLEO) . Radical scavenging activity of samples was assessed using Diphenylpicrylhydrazyl (DPPH). Total antioxidant capacity was assessed by methods phosphomolybdat. The amount of total phenol and flavonoid was assessed by Folin-Ciocalteu and Zhishen methods. Also, the components of FLEO were analyzed with gas chromatography/mass spectrometry (GC/MS). In FLHE and FLEO , total antioxidant capacity were 1.55 ± 0.13 and 1.09 ± 0.43 nmol, ascorbic acid equivalents/g, phenol content were 441.37 ± 2.50 and 76.56 ± 9.65 mg of Gallic acid equivalents (GAE)/g, and flavonoid content was 12.53 ± 3.20 and 0.015 ± 0.002 mg of quercetin equivalents/100 g respectively. In the DPPH scavenging assay, the IC 50 values of FLHE, FLEO and Butylated hydroxytoluene (BHT) as reference were 787.13 ± 3.66; 2375.66 ± 5.13 and 3.88 ± 1 ?g/mL respectively . Also GC/MS data and retention indices for reference essential oil leaves samples were used to identify 12 constituents. These compounds made up a total of 85.57% of FLEO : Eremophilene ; ? -cadinene ; Longiborneol; Dehydro aromadendrene; Isoledene; ? -Gurjunene; J-Guaiene. This study showed that ferula-assa-foetida has good antioxidant properties. As it is an easily-accessible source of natural antioxidants such as Eremophilene and ? -cadinene, it may be suitable for use in food and pharmaceutical applications. 52 0 http://ijpt.iums.ac.ir/browse.php?a_code=A-10-100-272&slc_lang=en&sid=1 Hassan Ahmadvand 1003194753284600915 1003194753284600915 No Hamze Amiri 1003194753284600916 1003194753284600916 No Zahra Dehghani Elmi 1003194753284600917 1003194753284600917 No Shahrokh Bagheri 1003194753284600918 1003194753284600918 No