Abstract: Pomposia fruits (Syzygium cumini) is rich sources of phenolic components. The aim of the current investigation was to evaluate the efficiency of pomposia extract as natural antioxidant compared with BHT as with the most commonly used synthetic antioxidant material. Therefore, sunflower oil was mixed with 200, 400, 800 and 1200 ppm of concentrated juice of pomposia were separately heated at 180±5°C, then 500 g of frozen French fries were fried every 30 min. Sunflower oil samples were heated at 180±5°C, frozen French fries were fried every 30 min during a continuous frying period of 12 h. Some physico-chemical properties (refractive index, viscosity, colour, acid value, peroxide value, thiobarbituric acid test and polymer content) of non-fried and fried oil were measured at various heating periods. The results of the current study indicated that mixing sunflower oil with the natural polyphenolic compounds of pomposia extract at level 800 and 1200 ppm oil increased the stability and hence improved the quality of sunflower oil during frying process.