Abstract: The corrosion state of steel oil tank is an important parameter for evaluating the safety of tank farm and the lifetime of oil tank. With complexed and varied factors of corrosion influencing oil tank, the blindness would be brought into cprrosion protection for lack of means of scientific management, The paper introduces the prediction of corrosion state of oil tank with application of grey model and the predictive model and the predictive method for inquiry of tank farm management.