Abstract: 【Objective】 This study aimed to identify the phloem protein 2 （PP2） gene family in cassava and conduct expression characteristic analysis， thereby providing theoretical basis for further investigating the mechanism of PP2 gene family in cassava for the response to abiotic stress. 【Method】 Based on cassava whole-genome data， members of PP2 gene family were systematically identified to analyze their chromosome localization， gene structures， as well as physicochemical properties， phylogeny， and evolution characteristics of their encoded proteins. The real-time fluorescence quantitative PCR was utilized to detect expression patterns of the MePP2s genes under different abiotic stresses. 【Result】 A total of 18 PP2 gene family members （MePP2s） were identified from cassava genomes， and they were named MePP2-1 to MePP2-18 in the order of their chromosomal locations， which were distributed on 10 chromosomes， encoding 166-346 amino acids， with the relative molecular mass of proteins of 19252.29-38785.00 Da， theoretical isoelectric points of 5.46-8.83. Among them， 10 were acidic proteins， 1 was neutral protein， and 7 were basic proteins respectively， and they located in the nucleus， cytoplasm， chloroplast， and cytoskeleton. Phylogenetic analysis results showed that 18 cassava MePP2s proteins and 30 Arabidopsis thaliana AtPP2s proteins were classified into four groups. The MePP2s proteins were mainly clustered in Group Ⅰ and Group Ⅲ，while the AtPP2s proteins were mainly clustered in Group Ⅰ and Group Ⅱ，demonstra-ting the differences in evolutionary characteristics between species. The same group shared similar gene structures and conserved motifs， and the cis-acting elements in gene promoters were mainly associated with light response， hormone response， and abiotic stress response. According to collinearity analysis， three pairs of segmental duplication genes and four pairs of tandem duplication genes were identified， and these duplication genes were mainly concentrated in Group Ⅰ and Group Ⅲ， with their evolutionary processes mainly under purifying selection. The real-time fluorescence quantitative PCR showed that under salt， drought， low-temperature， and oxidative stresses， the expressions of most genes showed an upward trend or an initial increase followed by a decrease trend with the extension of stress time， but there were significant differences among different genes， tissues， and stresses. 【Conclusion】 The expression of PP2 gene family members in cassava is regulated by various environmental signals and plant hormones， showing obvious tissue specificity and stress specificity. It is speculated that the genes of this family play an important role in growth， development， and stress response of cassava.