Background　Protectin D1 （PD1） is a new bioactive molecule derived from docosahexenoic acid （DHA）， it is an important kind of endogenous lipid anti-inflammatory and pro-resolution medium.　Objective　Expanded understanding of PD1 contributes to investigate the pathogenesis of a variety of diseases and provide new targets for its treatment.　Content　Numerous studies suggest that PD1 can act on inflammatory cells and inflammatory-related genes， and improve the prognosis of many kinds of diseases， activate inflammation-resolution programmes. This review presents an update and overview of PD1 about its biological activity and its effects on inflammatory cells and inflammatory diseases.　Trend　With further research， it will fully reveal the pathophysiological significance of the PD1 and clarify the mechanism of its effects. It is thought that people will open up the clinical value of new anti-inflammatory drugs based on PD1.