Nowadays, finding new resources of vegetal antioxidants in order to use them in food (as an additive or alternative with artificial antioxidants) is an important research subject in the field of food science and technology. In this research methanol and aqueous extracts of two varieties of date palm fruit (Mozafati and Rabi) were obtained. Then, two concentrations of each extract (2000 and 3000 ppm) were applied in free antioxidant-purified sun flower oil. The oils were kept in 68°C for a period of one month. After storage, Peroxide index of oil samples were determined. According to the results, Two extracts had significant difference in case of total phenolic content (p <0.05) and methanol extracts of Rabi variety had higher that Mozafati in these case. Oil samples containing 2000 ppm methanol extracts of Rabi, had better quality and stability than other samples and had no significant difference with BHT at 200 ppm concentration.