AIM: To investigate the method of directed differentiation dendritic cells(DC) from embryonic stem cells,and to amplify high purity dendritic cells in vitro for immunolgical therapy.METHODS: E14 embryonic stem cell line was generated ES-DC in complete medium supplemented with GM-CSF and IL-3.Flow cytometry was used to determine CD11c,CD80,CD86,MHC-II cell-surface phenotype in immatured ES-DC.Lipopolysaccharide(LPS) was added to induce the ES-DC maturation.The matured ES-DC was harvested 24 hours later to identifying with morphology and transmission electron microscopy.The phenotype of matured ES-DC was analyzed by flow cytometry and compared with the immatured ES-DC.The antigen presenting was evaluated by mixed lymphocyte responses(MLR).RESULTS: The ES-DC had obviously dendritic processes under scanning electron microscope.The immature DCs expressed low level of CD11c(4.33±0.23)%,CD80(7.62±0.19) %,CD86(4.77±1.22) % and MHC-II(9.68±0.15) %.The mature DCs expressed higher level of CD11c(47.36±2.68)%,CD80(74.40±1.47) %,CD86(29.77±2.00) % and MHC-II(87.56±2.75) %.MLR showed that ES-DCs effectively stimulated lymphocyte proliferation.CONCLUSIONS: These results provide evidence that dendritic cells can be generated from E14 embryonic cells with the stimulations of GM-CSF and IL-3.The differentiated cells expresse high level of CD11c,CD80,CD86,MHC-II and effectively stimulate lymphocytes to proliferate.ES cells may become new origin of DC for immunotherapy.