The effects of 2.5, 4.5, 6.5, and 8.5 ppm dissolved free oxygen on volatile compounds formation and dissolved free oxygen disappearance in oils during storage were studied. The amount of compounds formed in oil containing 8.5 ppm was double that in oil containing 2.5 ppm oxygen. The rate of oxygen disappearance in oil containing 8.5 ppm was three times as fast as that in oil containing 2.5 ppm oxygen. The rates of dissolved oxygen disappearance and formation of volatile compounds were significantly different for the four levels of dissolved oxygen (P < 0.05). As the initial oxygen concentration in oil increased, the rate of oxygen disappearance and the amount of compounds formed increased. The results indicate that the formation of volatile compounds in oil during storage can be minimized by lowering the oxygen content.