Abstract: Due to adverse effects of synthetic antioxidants on humans, it is logical to use antioxidants from natural sources in eatable oils and fats. Vast experimental studies have been proven antioxidant properties of Ferulago angulata, which basically belongs to west of Iran. Traditionally this plant was added to different products to prevent from decay as well as give them a pleasant taste. Different concentration of essential oil and extract were added to vegetable oil. Peroxide and Thiobarbituric indexes of samples were determined and compared with blanks samples (without any antioxidant and with TBHQ) showed that minimum concentration of extract for conserving of vegetable oil is about% 0.02 under excremental conditions. Extract with 0.5% concentration is more effective than TBHQ.