Abstract: Vegetable oils were extracted from soybean,sunflower seed from two different places,white peanut,black peanut, white sesame, black sesame, rapeseed, and cottonseed with Soxhlet extraction method.Composition of fatty acid and relative content were determined in nine kinds of vegetable oils by gas chromatography-mass spectrometry. It had been proved that compositions of fatty acid were different in different kinds of vegetable oils. Compositions of fatty acids were the same with same kinds of vegetable oils,and the relative contents were no major difference although producing area and breed of vegetable oils were different. The highest two relative content of two kinds of fatty acids in vegetable oils were 9,12- linoleic acid and 9- oleinic acid except rapeseed oil. The sum of the relative contents of the two kinds of fatty acids could also be used to distinguish different kinds of edible vegetable oil. According to recommended intake of saturated fatty acid,monounsaturated fatty acid and polyunsaturated fatty acids in edible vegetable oil in our country peanut oil was most approximate.