Abstract: Seven kinds of vegetable oil including olive oil, peanut oil, corn oil, rapeseed oil, sunflower oil, palm oil, soybean oil, were determined of fatty acid composition and content by gas chromatography-mass spectrometry (GC-MS) with optimized experimental condition. According to the data of fatty acid composition and content in edible vegetable oils, cluster analysis was use to classify the vegetable oil. A method was established in the identification of olive oil adulteration by gas chromatography-mass spectrometry, results showed that with the proportion of cheap oil adding to olive oil varied, the content of the fatty acid composition including myristic acid, -linolenic acid, docosanoic acid, trans linoleic acid, arachidic acid, eicosenoic acid changed linearly. The minimum detection limit of adding palm oil, rapeseed oil, soybean oil, corn oil, peanut oil and sunflower oil, respectively, was 5.27%, 5.61%, 6.35%, 4.53%, 1.93% and 9.21%. The qualitative and quantitative analysis of characterstic fatty acid could provide reference for appraisal of olive oil adulteration.