Abstract:A total of 143 (Agropyron cristatum ( L.) Gaertn.) germplasm resources from 10 cities and regions in Inner Mongolia were studied.Through the analysis methods of coefficient of variation, genetic diversity index, correlation, principal component, clustering and grey correlation,The diversity level of phenotypic traits of 143 samples of Agropyron cristatum ( L.) Gaertn. germplasm resources in Inner Mongolia was analyzed, and excellent germplasm resources were screened, which provided reference for germplasm resource innovation and variety breeding of Agropyron cristatum ( L.) Gaertn.The results showed that the 17 phenotypic traits of the species had great variation and rich genetic diversity. The coefficient of variation ranged from 93.92% to 11.47%, with an average of 42.80%. The coefficient of variation of leaf width was the highest, and the dispersion of seed length was the lowest. The genetic diversity index (H") ranged from 1.279 to 2.025, with an average of 1.72. The diversity index of glume length was the highest, and lowest for spikelet length.Correlation analysis shows significant or extremely significant correlations between various traits.Principal component analysis showed that the contribution rate of the first six principal component factors was 5.934% ~ 20.885%, and the cumulative contribution rate was 69.866%.The 143 germplasm were divided into 3 groups by cluster analysis, and the characters of each group were different and the characteristics were prominent. Class I had the best comprehensive traits, with prominent spikelet number and floret number, and had high yield potential, including 27 resources. The second type, containing 23 resources, had general traits and higher seed traits. The third type was poor in general character and long in plant height, containing 93 resources. Agropyron cristatum ( L.) Gaertn. species have abundant phenotypic genetic diversity.It is feasible to use the grey correlation method to comprehensively evaluate the germplasm of Agropyron cristatum ( L.) Gaertn. The comprehensive performance of the species of Agropyron cristatum ( L.) Gaertn. could be quantified, and the 1000-grain weight, spikelet number, Leaf tongue length, leaf width and leaf area were used as germplasm evaluation indexes.Selected excellent germplasm with coordinated comprehensive traits such as A-24, A-23, A-25, A-22, A-35, A-43, A-18 A.cristatum materials, and A-142, A-92, and A-136 A.cristatum var.pluriflorum materials, which can be used for genetic improvement and breeding of ice grass germplasm.