[Objective] Bacillus subtilis can induce efficient intestinal mucosal immune responses, but the detailed mechanism for dendritic cell activation remains to be defined.[Methods] Mouse intestinal epithelial CMT93 cells were stimulated with different concentra amyloliquefaciens tions of Bacillus subtilis and the cytokine expression was measure by quantitative RT-PCR and ELISA. After incubation with the cytokine-containing cell culture medium, activation of mouse bone marrow-derived dendrites (BMDC) was analyzed by flow cytometry and the role of IL-33 in BMDC activation was confirmed by RNA interference.[Results] Bacillus subtilis could significantly stimulate CMT93 cells to secret IL-6, IL-33 and IFN-g, and induce the IL-33 selection in a dose-dependent manner. The cytokine-containing cell medium could significantly activate BMDC. After interfering IL-33 gene expression and stimulation with Bacillus subtilis, however, the ability of CMT93 cell medium for BMDC activation was significantly reduced.[Conclusion] These data suggest that IL-33 from Bacillus subtilis-stimulated mouse intestinal epithelial cells plays an important role in the dendritic cell activation.