Objective:To observe the phenotype and functional changes of murine bone marrow derived dendritic cells loaded the insulin B9-23 peptide,and investigate its impact on the immune state of DCs. Methods:①Murine bone marrow cells were induced to differentiate into DCs by 10 ng/ml GM-CSF and 10 ng/ml IL-4,and then devided into blank control group,insulin B9-23 peptide stimulated group and LPS stimulated group.②CD40,CD80,CD86,CD11c and MHC-Ⅱexpressions were detected using flow cytometry. ③The stimulating allogenic lymphocytes proliferation abilities of these DCs were checked by CCK-8. ④ELISA was used to measure IL-12 and IFN-γ concentrations of the DCs culture supernatants. Results:CD11c expression was over 60% in all three groups;compared with the blank control group,the insulin B9-23 peptide group expressed low level CD40 and intermediate level CD80,CD86,MHC-Ⅱ,LPS group DCs expressed CD40,CD80,CD86 and MHC-Ⅱat high level. Meanwhile,DCs in insulin B9-23 peptide group showed increased ability to stimulate allogenic T cells proliferation,and the IL-12 consentration was significant higher while the IFN-γ concentration was a little lower than the blank control group. Conclusion:Stimulation by lnsulin B9-23 peptide generates semi-mature DCs. It is very meaningful for further studies,in which DCs loaded with insulin B9-23 peptide immune NOD mice to induce immunotolerance to prvent autoimmune diabetes.