Abstract: OBJECTIVE To study the effect of Panax notoginseng saponins (PNS) on TNF-α-induced proliferation of Mesangial cells and expression of matrix metalloproteinases(MMPs) and tissue inhibitors of metalloproteinases(TIMPs).METHODS Proliferation of SV40 MES 13 cells was induced by TNF-α. Real-time cell analysis system was used to record 120 h cell index (CI). The mRNA level of MMP-2 and TIMP-2 were measured by qRT-PCR. The expression of MMP-9 and TIMP-1 were measured by ELISA. RESULTS All three dose groups of PNS could inhibit the cell proliferation induced by TNF-α, of which 96 h effect was obvious. High, medium dose groups could significantly increase the ratio of MMP-2/TIMP-2 and MMP-9/ TIMP-1 compared with TNF-α group(P<0.05). CONCLUSION PNS can inhibit the proliferation of Mesangial cells induced by TNF-α, and the mechanism may be related to the improvement of MMP-2/TIMP-2, MMP-9/TIMP-1 balance.