Abstract:SWEET (sugar will eventually be exported transporters) protein participates in the loading of phloem sugars. In this study, 9 BeSWEET sequences were screened based on the transcriptome library of Bambusa emeiensis and analyzed by bioinformatics; Genes of BeSWEET42 and BeSWEET1a2 among the 9 BeSWEET sequences were cloned with the cDNA of the stem and young leaf of B. emeiensis. Real time quantitative expression analysis (qRTPCR) was used to analyze its expression levels in mesophyll, veins, roots, stems and the expression changes of BeSWEET gene induced by exogenous sugar. The results showed that: (1) phylogenetic tree analysis showed that 9 BeSWEET sequences were divided into four clades. BeSWEET42 which has two MtN3 conserved domains is homologous to rice SWEET4, clustered into Clade Ⅱ. BeSWEET1a2 is homologous to rice SWEET1a and SWEET1b, and clustered into Clade Ⅰ. (2) Sequence analysis showed that BeSWEET42 and BeSWEET1a2 encode 256 and 222 amino acids, respectively, and have 7 and 5 transmembrane domains, respectively. (3) The prediction of subcellular localization indicates that both genes are located in the plasma membrane. (4) qRTPCR analysis shows that BeSWEET42 and BeSWEET1a2 are mainly expressed in roots and veins, respectively. It is speculated that they may cooperate in the transport of carbohydrates from source to sink. (5) Both BeSWEET42 and BeSWEET1a2 were significantly upregulated under the induction of hexose, showing a preference for hexose. Our study provides the insight for understanding of biological functions of B. emeiensis BeSWEET proteins in regulating sugar transport.