Abstract: In order to prodvide evidence for further research and utilization of phlorotannins, structure of phlorotannins from brown algae were analyzed, research progress on the biological activity of antimicrobial, antioxidant, anticoagulant, antitumor activity and chemical defensive were reviewed, and the extract effect of different extract methods including organic solvent infusion, ultrasonic extraction, microwave extraction and organic solvent purification were compared.