Abstract: Mice were immunized with Campylobacter jejuni-S₁₃₁(CJ-S₁₃₁) to establish the lupus-like model. Splenocytes from lupus like mice were challenged with CJ-S₁₃₁ to induce inflammatory response in vitro. Bupleurum smithii var. parvifolium polysaccharides (BPs) was added in the inflammatory model to observe its underlying mechanisms of action on lupus. BALB/c mice were randomly divided into three groups including normal control group, adjuvant control group and lupus-like model. Mice were immunized on Day 0 and 14 with CJ-S₁₃₁ to establish lupus-like syndrome, and sacrificed on Day 19. Splenocytes from each group were collected and divided into blank control group, BPs added group (BPs 5, 10, 20, 40 μg·mL^-1), CJ-S₁₃₁ stimulated group, and CJ-S₁₃₁ plus BPs group. The levels of total IgG, anti-dsDNA antibody, interferon-γ, interleukin-10(IL-10) and IL-17 were quantified by ELISA. The proliferation of splenocytes was determined in the MTT assay. BPs significantly suppressed the high levels of total IgG, anti-dsDNA antibody, IFN-γ and IL-10 stimulated by CJ-S₁₃₁ and had no significant effects on increased IL-17 secretion and splenocytes proliferation. The results suggest that re-stimulation of splenocytes with CJ-S₁₃₁ could establish an inflammatory model in vitro. The effect of BPs on lupus might is related to its inhibition of the production of autoantibodies and associated cytokines.