Rosmarinic acid (Rosmarinic acid, RosA for short) is a water-soluble natural phenolic acid compound isolated from rosemary, a plant of the family Lamiaceae. It is widely distributed and mainly exists in Lamiaceae, Boraginaceae, and gourd Among a variety of plants in the family, Tiliaceae and Umbelliferae, the highest content is especially in the Lamiaceae and Boraginaceae. Rosmarinic acid is a natural antioxidant with strong antioxidant activity and helps prevent cell damage caused by free radicals, thus reducing the risk of cancer and arteriosclerosis. Rosmarinic acid has strong anti-inflammatory activity, and rosmarinic acid also has antibacterial, antiviral and antitumor activities. At present, rosmarinic acid has demonstrated its important application value in the fields of pharmacy, food and cosmetics.