Abstract: To get immature dendritic cells (imDC),mononuclear cells from bone marrow of rats were isolated and purified,with recombinant rat granulocyte-macrophage colony stimulating factor (rrGM-CSF) and recombinant rat interleukin (rrIL-4) being added to the medium.Semimature dendritic cells (smDC) was obtained by being stimulated with tumor necrosis factor-α(TNF-α),simultaneously mature dendritic cells (mDC) was obtained by being stimulated with Lipopolysaccharides(LPS).The three kinds of dendritic cells were identified by morphology,expression of the cell surface markers and cytokines,the activation of allogeneic lymphocytesby different kinds of DCs was tested.The results were according with the pertinent literatures.In other words,the cells in the culture system were imDC,smDC and mDC.Therefore it is a feasible way to induce myeloid monocytes to differentiate into different mature states of dendritic cells by using the stimulation of GM-CSF, IL-4 and TNF-α.