Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Most patients with sepsis underwent a state of immune suppression after surviving the acute inflammatory response, and were susceptible to secondary nosocomial infections, leading to a prolonged hospitalization and increased mortality rate. Myeloid-derived suppressor cells (MDSCs), a heterogeneous population with immunosuppressive activities, can contribute to the development of immunosuppression in patients with cancer and inhibit the host immune response, but the characteristics of MDSCs and their functional mechanism has not been fully addressed in the development of sepsis-induced immunosuppression. Thus, this review will summary the new findings on the mechanisms of MDSCs in septic immunosuppressionin order to provide ideas and directions for targeting MDSCs as treatment of septic immunosuppression.