AbstractThe ratios of stable carbon isotopes (δ13C) of 12 oils extracted from Chinese edible oilseed samples and their individual fatty acids were determined by elemental analysis‐isotope ratio mass spectrometry (EA‐IRMS) and gas chromatography‐isotope ratio mass spectrometry (GC‐IRMS). The results have demonstrated that the δ13C ratios of the oils from C3‐plant seeds range from −26.8 to −30.7‰, while the δ13C ratios of C4‐plant maize oil are in the interval of −14.1 to −16.2‰. Eighteen fatty acids were identified and their abundances were measured by gas chromatography–mass spectrometry (GC–MS) in these oils with C16:0, C18:0, C18:1 and C18:2 as the major constituents. From the data on fatty acids and stable carbon isotopes, several sensitive markers were developed to detect the adulteration of Chinese edible oilseed oils. Examples are provided with pre‐blended samples to illustrate the discrimination procedures and corresponding sensitive markers with emphasis on camellia seed oil, flax seed oil and perilla seed oil.