Ulvans are structural polysaccharides present in the cell walls of green algae such as Ulva armoricana, Ulva rotondata, Ulva rigida, Ulva lacterca & Ulva pertusa. They are highly sulphated and contain rhamnose 3-sulphate, xylose, xylose 2-sulphate, glucuronic acid and iduronic acid residues. Ulvan has several potentially valuable functionalities such as gel formation for agricultural and food applications and possible anticoagulant, antioxidant, antihyperlipidemic and antitumor activities for pharmaceutical applications.