Abstract:This study attempted to study the genetic diversity of Armeniaca vulgaris var. ansu germplasm provenances. Fifteen qualitative indexes and 25 quantitative indexes of 54 clones were investigated and subjected for cluster analysis, correlation analysis, principal component analysis and stepwise linear regression analysis. The results showed that the phenotypic traits of 54 Armeniaca vulgaris var. ansu clones have a high degree of variation, diverse types and rich genetic diversity. Among them, the average variation coefficient of the 25 quantitative indexes was 18.19%, with the largest variation coefficient on single fruit weight (42.56%). The mean of Shannon-wiener index in quantitative indexes (1.980) was greater than that in qualitative indexes (0.761), the Shannon-wiener index of leaf-form index was the largest (2.082). The Armeniaca vulgaris var. ansu clones were divided into five groups, including: Group Ⅰ contained germplasm resources with high nutlet rate, high kernel rate and special leaf shape; Group Ⅱ, which included germplasm resources with special types of fruit; Group III contained elite lines with potential use in breeding for special nutlet and kernel types; Group IV contained the germplasm with large-nutlet, large-kernel, and high-yield; Group V contained nutlet shell resources. Principal component analysis indicated that the first seven principal components of the 25 quantitative indexes explained 83.31% of the cumulative contribution rate. An elite line No.270 from Huining county of Gansu province represented a highest comprehensive score.By analysis together with stepwise linear regression method, 11 indexes, including branchlet width, leaf length, fruit length, single fruit weight, nutlet length, nutlet width, nutlet thickness, single nutlet weight, kernel width, kernel shape index and nutlet rate, were proposed as important indexes to evaluate phenotypic variations of Armeniaca vulgaris var. ansu clones.