Abstract:Because of its probiotic functions，Bifidobacterium longum attracts widespread attention. This paper aimed to reveal the genetic characteristics of Bifidobacterium longum W13 and to analyze its functional genes and metabolic pathways based on genome-wide analysis. The results showed that strain W13 belongs to Bifidobacterium longum subsp. Longum. The annotation of evolutionary genealogy of genes: non-supervised orthologous groups（eggNOG）database revealed that amino acid metabolism and carbohydrate metabolism were the main metabolic functions of this strain. The annotation of kyoto encyclopedia of genes and genomes（KEGG）database revealed that the strain contains more quorum sensing genes，indicating that this strain can promote intestinal homeostasis. The annotation of the carbohydrate-active enzyme（CAZy）database manifested that the strain had a high capacity for sugar synthesis. Finally，comparative genomic analysis showed that Bifidobacterium longum subsp. longum enjoyed great genetic diversity and stability and strain W13 had its specific functional genes compared to other Bifidobacterium longum subsp. longum. In conclusion，the strain W13 provides certain probiotic functions and has the potential to be developed as a probiotic.