Hornwort, edible, alias: deer hornwort, Qingdao people called Longshu Cai; belongs to the brown algae, cedar algae, hornwort genus, natural distribution in the Atlantic coast and China's southeastern coast as well as Qingdao, Dalian and other waters, is an important economic seaweed in China. Carrageenan is not only an important original algae for carrageenan production, but also more and more used in the field of medicine in recent years, which has attracted widespread attention.