Dysfunction of dendritic cells is one of main reason in sepsis which induced immunosuppression.The number of dendritic cells ,especially immature dendritic cells,decreased significantly.Which lead to its devouring antigen ability weakened. Much of dendritic cells,which were from the spleen of septic mice,stayed as mature phenotype,with the imbalance between the secretion of cytokines(IL-10,and IL-12).Compared with normal mice,the dendritic cells ,which isolated from septic mice, could not stimulate T cells proliferation efficiently.The characteristic mentioned above caused the body have no responses to foreign pathogen.as a result lead to the body in immunosuppression states.