Oxidation of fats and oils causes a decrease in sensory properties and nutritional value of these products. In order to prevent oxidation, several actions might be employed. among them, application of antioxidants is common. Todays, synthetic antioxidants such as BHA, BHT, TBHQ and gallat esters are used as food antioxidants. Restriction on the use of these compounds, however, is being imposed due to their potential health hazards. Beside of their relative safety, natural antioxidants may also play a pivotal role in preventing heart disease and cancer. Mint, spearmint and basil are aromatic herbs that most of their species are native to Iran which belong to Lamiacae family. In traditional medicine they are used as antibloating, antiepileptic, stimulator, gastric acid inhibitor, peptic ulcer pacifier, anal medicine. Because of having abundant amount of phenolic compounds these herbs have also considered as natural source of antioxidant that could be use instead of synthetic antioxidants. In this study, different solvent (water, methanol and ethanol) were used to extract phenolic compounds from mint, spearmint and basil then total phenolic content was determined according to the Folin-Ciocalteu method. Using methanol solvent with ultrasonic extraction method had the most efficiency for the herbs. Among the herbs, spearmint contained the most extracted phenolic compound (67.22 mg/gdw). According to first part of this study, methanol extracts from the herbs were used as antioxidant substitutes compare to synthetic antioxidants (BHT, BHA and TBHQ), in edible oils. In second part, effect of methanol extracts (at 200, 400 and 600 ppm) was compared with effect of synthetic antioxidant (at 100 and 200 ppm) to retard oxidation by determination of peroxide value and thiobarbitoric acid. Results indicated, the different concentration of phenolic compound in the herbs were able to retard the oxidation but effect of methanol extract at 600 ppm is comparable with the effect of synthetic antioxidants at 200 ppm. Spearmint was the most effective antioxidant among herbs followed by mint and b
