Abstract: Macrophages are important components in human innate immune system. They are highly plastic and can differentiate into pro-inflammatory M1 and anti-inflammatory M2 under the stimulation of different microenvironmental signals. Polarization of macrophages is regulated by many signaling pathways and transcription factors, and M1/M2 phenotype are involved in the occurrence and development of a variety of diseases, such as tumor, type Ⅱ diabetes and severe acute pancreatitis, etc. In this paper, we reviewed the main signaling pathways related to macrophage polarization and its polarization state in common disorders, and described the importance of balance of macrophage polarization in maintaining homeostasis, with an attempt to provide new ideas for related clinical research. 

Key words: Macrophage polarization, Tumor, Metabolic diseases, Inflammatory diseases