Trans fatty acids content and composition of 76 food products of 7 seven kinds of food were surveyed.This paper utilizes an internal standard(IS) to determine the content of trans fatty acids.The results showed that the contents of TFAs in 68% of samples were not higher than 0.3 g/100g,in 29% of samples were ranging from 0.3 to 2.0 g/100g,in 3% of samples were higher than 2 g/100g.In addition to rice crust and the puffed food,the main kind of TFAs was C18∶ 1t.The total content of C18∶ 1t accounted for 60%~96% of total TFAs.Conclusion Except a few foods,TFAs was widely present in most of foods with low levels.