Abstract：In order to fully explore and utilize the germplasm resources of proso millets, this study took 490 proso millets germplasm resources as materials, grouped them based on variety type and spike shape, and relied on the square root proportion method to determine the number of samples, and within the group according to 20 qualitative and quantitative traits for cluster analysis and random sampling method within the group for constructing the core germplasm. The representativeness of the backbone germplasm of proso millets was evaluated using the indexes of mean, variance, coefficient of variation, genetic diversity and proportion of traits retained, and confirmed by principal component analysis, histogram and correlation. The results showed that 55 proso millets core germplasms were constructed, accounting for 11.2% of all germplasm, including 26 local varieties (47.26%), 9 bred varieties (16.36%), 9 wild varieties (16.36%), and 11 points foreign varieties (20.00%). The results of significance analysis showed that the differences between the core germplasm of proso millets and all the germplasm in terms of mean, variance, coefficient of variation and genetic diversity of phenotypic traits were not significant (p > 0.05), and the constructed core germplasm basically retained the distribution range of all the germplasm. The results of correlation analysis showed that the significant differences in phenotypic traits between the core germplasm and all the germplasm of proso millets were also generally consistent.