Abstract: During production, storage and transportation and treatment of product oil, it is necessary to treat the contaminated product in order to avoid depreciating from product oils' mixing. Five treating methods of contaminated product are often used, that is, back tail treatment, distillation, metal-oxide treating, caustic treating and filtration. The study results have shown that because these methods have their own advantages and disadvantages, the necessary consideration should be taken into their application based on different situations.