Chemical composition and ascorbic acid were estimated in tubers of four potatoes varieties (Oceania, Pamina, Lady Rosetta, and Lady Balfour) collected from storage refrigerator. The study showed differences in chemical composition between the four varieties. The protein, fat, carbohydrates, ash, fiber, moisture and ascorbic acid content  ranged respectively from 6.78-8.2, 0.2-0.3, 81.01-84.1, 5.36- 6.97, 3.47-471, 78.1-86.21, and 18.92-25.08 % in the varieties investigates. The statistical analysis show highly differences between the four kinds of potatoes. High percent of protein, fat and ascorbic acid were detected in Lady Rosetta potato, of ash and moisture in Pamina potato, of carbohydrates in Oceania potato, while of fiber in Lady Balfour potato. The antioxidant enzymes peroxidase, Catalase and Ascorbate peroxidase were determined, showing ranges of 0.05-0.13, 0.15-0.2 and 0.12- 0.31Unit min-¹ gm-¹ in Oceania, Pamina, Lady Rosetta and Lady Balfour, respectively.