Genetically modified soybean oil has ranked the largest edible vegetable oil in China. Scientific and reasonable labeling regulations enable the right to know the transgenic soybean oil， guarantee the freedom of choice for consumers and promote a healthy and orderly soybean oil market. To guaranty the implementation of these regulations， analytical methodologies allowing accurate determination of genetically modified soybean oil are demanded. DNA analysispresentsa high sensitivity， specificity and durability compared to chemical analyses and proteins analyses which lack a reliable performance with highly processed samples. The DNA extraction protocols and PCR amplification were systematically summarized to promote a successful genetic characterization. At last， the DNA degradation caused by the oil refining process was reviewed.