Abstract: The psychrophilic and barotropic bacterium Shewanella psychrophila WP2 was previously isolated from deepsea sediments. Intriguingly, S. psychrophila WP2 possesses the largest genome (6.4 Mb) among Shewanella genus. In this study,the phylogenetic and metabolic potentials of S. psychrophila WP2 were investigated to deepen the understanding of the environmental adaptability of benthic microbes. The phylogenetic tree shows that psychrophilic/piezotolerant (including S. psychrophila WP2) and mesophilic pressure-sensitive Shewanella strains belong to the Group 1 and Group 2 branches, respectively. The number of genes involved in DNA repair, secondary metabolite synthesis and transport secretion in the S. psychrophila WP2 genome are significantly higher than that of S. piezotolerans WP3. Besides, S. psychrophila WP2 harbors 17 genomic islands which contain a variety of genes related to purine metabolism, amino sugar metabolism, motility, chemotaxis and quorum sensing as well as antibiotic secretion. Moreover, the results demonstrate that deepsea bacterium acquires a large number of functional genes which have enhanced its abilities of nitrogen source utilization, moving and chemotaxis, as well as group sensing to the complex environment and synthesis of antibiotics for more adaptation in oligotrophic and complex extreme deep sea environment. This study has conducted profound exploration and research on the metabolic potential of S. psychrophila WP2. It provides additional data reference and theoretical basis for future research on the environmental adaptation mechanism of Shewanella and microorganisms.