Abstract: Sepsis is one of the common critical diseases in intensive care unit (ICU), and the morbidity and mortality of sepsis remained high over the past decades. The latest definition of sepsis calls for timely recognition of the dysregulated host response to infection, as the resulting organ dysfunction can greatly endanger a patient’s life. Based on the definition and epidemiological data of sepsis, the pathophysiology of sepsis was discussed from the perspectives of inflammation, coagulation dysfunction, immunosuppression and organ dysfunction. At the same time, the nuclear factor κB(NF-κB), Janus kinase (JAK)/signal transduction and activator of transcription (STAT), phosphate inosine 3-kinase (PI3K)/ serine/threonine kinase (Akt) and mitogen-activated protein kinase (MAPK) were introduced to summarize the progress of research on sepsis. It is expected to lay a theoretical foundation for clinical research and prevention of sepsis and ultimately improve the treatment level of sepsis.