Sepsis is defined as an organ dysfunction caused by systemic inflammatory response induced by infection,and may eventually developed into multiple organ failure (MOF).The onset of sepsis often involves the activation of inflammatory cells,over expression of inflammatory cytokines,immune dysfunction,damage of tissue and organ,excessive apoptosis of cell.Mesenchymal stem cells (MSCs) have a wide range of biological activities,including anti-inflammatory,antibacterial,immune regulation,regeneration and repair of tissue and organ,anti-apoptosis,etc.In recent years,a large number of preclinical studies had demonstrated that MSCs has good actions on sepsis.The purpose of this review is to describe the mechanism of MSCs in the treatment of sepsis,and to point out the possible clinical challenges.