A study is made of the reaction of rolled vanadium sheet with oxygen over the temperature range of 400° to 600°C using specimens weighing 0.1264 g and having a surface area of 1.4 cm2. The data may be fitted to the parabolic rate law except for the initial period of the reaction. A plot of gives an energy of activation of 30,700 calories per mole. The oxidation of vanadium may be compared to the corresponding reactions on columbium and tantalum since the oxide is soluble at high temperatures and the extent of reaction is of the same order of magnitude.