Objective：This study aims to explore the regulatory role of transcription factor Krüppel-like factor 5（KLF5）in the proinflammatory factor［i.e. interleukin（IL）-36α］production in rat glomerular mesangial cells（GMC） stimulated by sublytic C5b-9. Methods：First，the changes of KLF5 or IL-36α mRNA and protein at different time were examined by reverse transcription PCR（RT-PCR）and Western blot in the GMC stimulated by sublytic C5b-9. Then，the plasmids of KLF5 overexpression（pIRES2-KLF5）and KLF5 short hairpin RNA（shKLF5）were generated and transfected rat GMC respectively，and the cells were treated with or without sublytic C5b-9. The effects of overexpressing KLF5 gene or silencing KLF5 gene on IL-36α synthesis in the GMC induced by sublytic C5b-9 were detected by RT-PCR and Western blot. Meanwhile，the activity of IL-36α promoter after KLF5 gene overexpression or knockdown in the GMC was measured by luciferase reporter assay. Results：The mRNA and protein expression of KLF5 and IL-36α were obviously elevated in the GMC stimulated by sublytic C5b-9，and the expression phase of KLF5 was earlier than that of IL-36α. KLF5 overexpression could promote IL-36α production，but KLF5 knockdown markedly decreased IL-36α expression in the GMC upon sublytic C5b-9 incubation. Sublytic C5b-9 treatment or KLF5 overexpression could significantly up-regulate IL-36α promoter activity，but KLF5 gene knockdown remarkably declined IL-36α promoter activity stimulated by sublytic C5b-9. Conclusion：The up-regulation of KLF5 has a promoting role in IL-36α synthesis in rat GMC stimulated by sublytic C5b-9.