Abstract: To understand oil content and fatty acid composition of different selected superior trees of Carya dabieshanensis, taking the fruits of 18 selected superior trees as materials, oil content and fatty acid composition were tested. The results show that the oil content of superior trees is 48.6%-70.3%, CV is 7.83%, oil content of XZ5 is the highest which is 70.3%, the second is XZ2 which is 68.4%, oil content of JZH and ZZ2 is the lowest, which is only 55.9% and 48.6%. The maximum variation coefficient of linoleic acid among the fatty acid components of the superior trees is 21.23%; the second palmitic acid is 14.36%, the linolenic acid is 12.93%, and the stearic acid is 10.05%. The coefficient of variation of cis-11-eicosenoic acid, oleic acid and palmitic acid is small, 4.14%, 4.43% and 4.82%, respectively. The oleic acid content was highest at XZ5, which is 81.8%, followed by XZ1 and XZ2, which are 81.3% and 81.0%, respectively. Linoleic acid has a maximum ZZ2 of 17.8%, followed by GJC4 and ZW1, which are 17.5% and 17.2%, respectively. The coefficient of variation of polyunsaturated fatty acids is 20.07%, and the highest content is ZZ2, GJC3 and ZW1, which are 19.143%, 18.984% and 18.774%, respectively. The coefficient of variation of monounsaturated fatty acids is 4.40%, and the highest content is XZ5, XZ1 and XZ2, which are 81.976%, 81.480% and 81.181%, respectively. The coefficient of variation of saturated fatty acids is 5.79%, and the highest content of ZZ2 is 8.973%. There is a certain correlation between the fatty acid components of pecans in Dabieshan. There is a significant negative correlation between oleic acid and linoleic acid. The content of monounsaturated fatty acids is significantly negatively correlated with polyunsaturated fatty acids and saturated fatty acids