Alginate is the main component of the cell wall of brown algae. It has been reported that Pseudoalteromonas can produce alginate lyase, implying that the strains have the ability to degrade alginate. Whole genome sequencing of multiple species in Pseudoalteromonas have been carried out. Based on this, we performed a research on the utilization of alginate of this genus by using comparative genome analysis and experimental verification, aiming to reveal its degradation and metabolic pathways, and to lay a foundation for clarifying the degradation mechanism of particulate organic matters by marine bacteria.