Abstract:Theabrownins is a brown polymer rich in hydroxyl and carboxyl groups and possessing phenolic properties.It is generally extracted from dark tea，and is also prepared by chemical oxidation and enzymatic oxidation polymerization with tea polyphenols as substrate.Its physicochemical properties can be analyzed from the aspects of surface morphology，thermal properties，spectral properties and composition structure.As a natural active substance，theabrownins has many physiological activities such as anti-oxidation，anti-obesity，anti-cancer and regulation of intestinal flora，and thus it has a broad development prospect in food and medicine.In this paper，the latest research results on preparation technique，physicochemical properties and biological activities of theabrownins were reviewed to provide reference for further research and product development of theabrownins.