Abstract: The study explored the role of glycosyltransferase in inflammation response of embryo trophoblast cells infection by Brucella. WboA gene was amplified from Brucella melitensis M5-90 strain by PCR and cloned into vector pET-28a(+). The constructed recombinant plasmid pET-WboA was transformed to competent E. coli BL21. The protein WboA was identified by SDS-PAGE, Western blot, and purified. The suicide plasmid pGEM-7zf-ΔWboA-SacB was constructed. The WboA gene was knocked out of the genomic DNA of Brucella melitensis vaccine M5-90 strain by homologous recombination. Then purified the WboA protein and ΔWboA affects in the embryo trophoblast cells separately, the inflammatory cytokines of IL-6, IL-10, TNF-α and the lactic dehydrogenase (LDH) were ELISA examination. The protein WboA was successfully purified and the mutant ΔWboA was constructed. Compared with the M5-90 infected group, the HPT-8 cells infected by ΔWboA released much less inflammatory cytokine IL-6, IL-10 and TNF-α (P<0.05). The inflammatory cytokine IL-6, TNF-α  and LDH released by HPT-8 effected with WboA protein were significantly higher than the PBS control group(P<0.01). These results indicate that the protein WboA has the function of cytotoxin and the inflammation response of Brucella is related to the Lipopolysaccharides O chain.