Abstract:Macrophages are one of the most important inflammatory cells, named for their powerful phagocytic function. Macrophages phagocytosis of tissue fragments and foreign bodies plays an important role in the process of tissue healing in inflammatory response. Macrophage subtypes M1 and M2 participated in the pro-inflammatory and anti-inflammatory effects respectively, and M2 had four subtypes to promote the healing of injured tissues. When violence causes fracture, release cytokines IL-4, IL-10, IL-13, TNF-α, etc., recruit macrophages and other inflammatory cells to the fracture site, phagocytosis of tissue fragments and foreign bodies and releasing anti-inflammatory factors, such as vascular endothelial growth factor (VEGF) and other growth factors to create good conditions for fracture healing; therefore, to explore the role of macrophages in fracture healing. The role of the healing process is very important and provides new ideas for the future research and treatment of nonunion.