Objective: To explore the regulating effects of cefodizime on cytokines expression of neutrophil response to Klebsiella pneumoniae （Kle. p） treatment. Methods: We detected the types and expression of cytokines secreted by neutrophils by cDNA array and RT-PCR. We also analyzed the changes of signal transduction in this process by detecting the expression of toll like receptor 4 （TLR4） and the inhibitor factor of κBα （I-κBα） expressed by neutrophils. The activity of NF-κB DNA-binding in neutrophils was measured by electrophoretic mobility shift assay （EMSA）. Results: Cefodizime increased the neutrophils production of TNF-α

IL-1β and the mRNA expression of TLR4 in the early stage of Kle. p stimulation in mice

which seemed corresponding to the enhanced NF-κB DNA-binding activity. Conclusion: Cefodizime regulates the cytokines expression of neutrophils through the LPS-TLR4-NF-κB pathway by affecting the expression of TLR4 mRNA and the DNA binding activities of NF-κB in mice with the challenge of Kle. p.