Objective：To explore the regulatory role of KLF4，as a transcription factor，in the production of pro-inflammation cytokine IL-23 gene in rat glomerular mesangial cells（GMC）induced by sublytic C5b-9. Methods：The plasmids of KLF4 short hairpin RNA（shKLF4）and KLF4 overexpression（pIRES2-KLF4）were first generated and transfected rat GMC respectively，then the cells were treated with or without sublytic C5b-9. The roles of silencing KLF4 gene in IL-23 synthesis induced by sublytic C5b-9 or overexpressing KLF4 gene in IL-23 production were detected by qPCR，Western blot and ELISA. Moreover，the plasmid of IL-23 promoter（full-length，FL）was also constructed. After co-transfection，the activity of IL-23 promoter with or without sublytic C5b-9 after KLF4 gene knockdown or overexpression was measured by luciferase reporter assay. Results：①Sublytic C5b-9 could obviously elevate IL-23 production in rat GMC，and after KLF4 gene knochdown with shKLF4，the increase of IL-23 expression upon sublytic C5b-9 was remarkably diminished，but KLF4 overexpression in the GMC could markedly elevate IL-23 synthesis. ②The IL-23 promoter activity incubated with sublytic C5b-9 was significantly up-regulated. Meanwhile，after KLF4 gene knockdown，the IL-23 promoter activity in the GMC stimulated by sublytic C5b-9 was obviously declined，but KLF4 overexpression greatly increased IL-23 promoter activivy. Conclusion：Sublytic C5b-9 could induce IL-23 production of GMCs through the increase of KLF4 expression.