Abstract: Sepsis induced by major burns, trauma, and hemorrhage, remains a major cause of death of patients in intensive care units, and it may result in both the widespread activation and dysfunction of the innate as well as adaptive responses in host immune system. A large amount of information concerning subsets of innate and adaptive immune cells in sepsis has implicated that these cells, including neutrophils, macrophages, dendritic cells, T lymphocytes, regulatory T lymphocytes, and natural killer cells, have profound effects on immunoreactivity during acute insults or sepsis through modulating multiple receptor expressions or cytokine secretion, in turn contributing to the development and outcome of sepsis. It is of great significance that precision monitoring of immune function and the related indicators might help to assess the risk of secondary infection, the prognosis of septic patients, and guide the treatment of septic complications.