Objective To explore the role of NG2 proteoglycan in the pathogenesis of glomerulosclerosis. Methods Eukaryotic expression vectors carrying the small hairpin RNA (shRNA) for NG2 mRNA , named as Psilencer-NG2, was constructed. Then, rat mesangial cells (RMC) were transfeeted with Psilencer-NG2, Psilencer-NC (negative control), pcDNA/NG2 (NG2 over-expressive vector) and empty vector pcDNA 1 respectively. The expression of endogenous NG2 in RMCs was examined by real-time PCR and Western blotting. Cell proliferation was analyzed by MTT assay and flow cytometry. The expression of laminin was detected by real-time PCR. Results Transfection of pcDNA/NG2 into HBZY-1 cells resulted in over-expression of NG2 mRNA and protein (P<0.05, P<0.05). Transfection of Psilencer-NG2 led to reduced expression of NG2 mRNA and protein (P<0.01, P<0.01). The expression of laminin β1 significantly increased due to overexpression of NG2 and decreased by treating with NG2 siRNA. According to MTT assay, overexpreasion of NG2 significantly stimulated the proliferation of mesangial cells while NG2 silencing inhibited it. NG2 increased the cell number in S phase and decreased the cell number in G0/G1 phase, while silencing NG2 induced the decrease of cell number in S phase and the increase of cell number in G0/G1 phase. Conclusion NG2 actively participates in the pathogenesis of glomerulosclerosis by stimulating proliferation of RMCs and increasing the deposition of ECM.