Abstract: Macrophages are divided into classically (M1)-and alternatively (M2)-activated macrophage phenotypes.The former secrete pro-inflammatory cytokines to amplify inflammation, while the latter secrete inflammation inhibition factors to inhibit excessive inflammation and promote angiogenesis,tissue repair, tumor growth and so on. As an important second messenger, ROS not only lead to the production of proinflammatory cytokines,but also promote the occurrence and development of cancer.Under different stimulating conditions,ROS can transform macrophage into different phenotypes by regulating the polarization process,and further play different roles.

Key words: ROS, Macrophage, Polarization