Objective：This study aims to explore the effects of Cyclin D1 expression regulated by GCN5 and the acetylation modification of SOX9 by GCN5 in the glomerular mesangial cells（GMC）stimulated by sublytic C5b-9. Methods：Firstly，GCN5，SOX9 and Cyclin D1 expression in the renal tissue of Thy-1 nephritis（Thy-1N）rats（in vivo）and in sublytic C5b-9-treated GMC（in vitro）was examined using Western blot. Then the plasmids of pIRES2-GCN5 and shGCN5 or these plasmids with Cyclin D1 promoter plasmids were respectively transfected rat GMC，and Cyclin D1 gene initiation，transcription and expression were measured by luciferase reporter gene assay，real-time PCR and Western blot. Meanwhile，SOX9 acetylation was detected by co-immunoprecipitation（Co-IP） and Western blot in the GMC exposed to sublytic C5b-9 or transfected GCN5 overexpression or enzyme activity mutation（ΔGCN5）plasmids. Results：The expression level of GCN5，SOX9 and Cyclin D1 was significantly up-regulated both in vivo and in vitro，and GCN5 gene overexpression increased Cyclin D1 promoter activity，mRNA transcription and protein expression；GCN5 gene knockdown made for the opposite results. Besides，SOX9 acetylation was also elevated upon sublytic C5b-9 stimulation and GCN5 gene overexpression；SOX9 acetylation was reduced upon GCN5 knockdown. Conclusion：GCN5 can promote Cyclin D1 expression and acetylate SOX9 in GMC.