Abstract: Oenothein B(abbreviated OEB)is originally a macrocyclic dimer tannin isolated from the Oenothera erythrosepala. Early research focused on the antitumor activity of OEB in vitro and in vivo,and modern research has shown that it has various biological activities such as anti-inflammatory,immune regulation and antioxidant activity. Recently,the research papers on OEB at home and abroad have not been summarized,and their biological activity and mechanism research are not systematic and in-depth. This paper aims to review the research progress of OEB and its biological activity,which might provide ideas for further research and application.