【Objective】To explore the basic characteristics of CPP family members of foxtail millet and their response mode under exogenous selenium treatment, and to provide new genetic materials for the breeding of innovative varieties rich in selenium and high folate in foxtail millet. 【Methods】Using bioinformation tools to identify CPP family members, using qRT-PCR technology to determine CPP gene expression in various organizations and in exogenous selenium, which laid a foundation for revealing the biological function of CPP family and the response mechanism of exogenous selenium in foxtail millet. 【Results】(1) The millet genome contained 9 CPP genes, which were located on 6 chromosomes and were named SiCPP1-SiCPP9 according to the arrangement of genes in chromosomes. Amino acids ranged from 220 to 899, the relative molecular weight ranged from 23624.32 to 97253.16Da, and the isoelectric point ranged from 6.64 to 9.17, the number of introns ranged from 3 to 11, subcellular predictions showed that all family members could position themselves in nucleus. The prediction of the secondary structure of the protein indicated that the proportion of irregular curling and α-helix in the family was the heaviest.. (2) Phylogenetic analysis showed that gluten proteins could be divided into four subfamilies, the number and distribution of conservative elements and structural fields among the same subclans. (3) Promoter analysis revealed a large number of light, growth and development, hormone and stress response elements in foxtail millet CPP family. (4) Fluorescence quantitative results showed that CPP family members were differentially expressed in root, stem, leaf and ear.All 9 members of the millet CPP family were responsive to exogenous selenium, among which SiCPP5, SiCPP6, SiCPP7 and SiCPP8 were the most responsive. 【Conclusion】Members of the millet CPP family had tissue expression specificity and varying degrees of response to exogenous selenium.