Sepsis is defined as a life- threatening organ dysfunction caused by a deregulated host response to infection and is the leading cause of mortality in intensive care units. Although the exact pathogenesis of sepsis remains unclear，immunosuppression is considered to play a key role. Sepsis-induced immunosuppression is characterized by a failure to eradicate the primary infection and by development of secondary nosocomial infections， resulting in a prolonged hospitalization and increased death rate in sepsis patients. Early recognition of immunosuppression and appropriate intervention will benefit these patients. This review helps clinicians identify patients with immunosuppression through high-risk population screening and biomarkers detection，and introduces immunostimulants that have been used in clinics and clinical trials.