Objective  This paper aims to explore the composition, content difference and correlation of the components of pecans, and to provide a reference for the mining of superior germplasm resources and the breeding of superior new clones.

  Method  The oil content, fatty acid, phenolic substance content, drupe mass, drupe height, drupe diameter, and kernel mass of 50 clones were measured to analyze the correlation among the traits, and comprehensive evaluation was made based on the principal component analysis model.

  Result  (1) The oil content ranged from 70.09% to 79.99%, among which the mean oil contents of JD25, JD13, JD6, JH3, JD23, XS3, JD27 and JD28 were higher. (2) A total of 8 kinds of fatty acids were detected, and the relative contents of fatty acids were different, among which the contents of JH1, JD21, XS3, JD27 and XS7 unsaturated fatty acids were higher than those of other varieties. (3) There were significant differences among traits, and the variation coefficient of unsaturated fatty acids was 0.38%, which was the most stable one. The coefficients of variation of total flavonoids and condensed tannin were 51.22% and 49.88%, respectively, which were high variables. (4) Principal component analysis was used to comprehensively evaluate the 50 clones, among which, XS12, XS1, JD23, XS3, JH1, XS8, JD30 and JD29 ranked the top.

  Conclusion  Considering the comprehensive oil content and principal component analysis model ranking, the top 3 clones of each and the clones shared by both, i.e. JD23, XS3, XS12, XS1, JD25, JD13 and JD6 are selected as excellent germplasm resources and excellent clones for cultivation and breeding.