Abstract： Objective： To discuss the curative effect of extract of Radix Polygoni Multiflori on rats with mesangial proliferative glomerulonephritis(MsPGN) and its effect on the expression of nuclear factor kappa- B(NF- κB) in the kidney tissue. Methods： A total of 40 Wistar rats were randomly divided into the control group， the model group， the extract of Radix Polygoni Multiflori group and the Lotensin group according to their body mass，10 rats in each group. Except those in the control group，rats in the other groups were given renal resection on one side and continually injected with OX7 antibody to induce MsPGN rat models. After four-week injection，the extract of Radix Polygoni Multiflori group and the Lotensin group were respectively given extract of Radix Polygoni Multiflori and Lotensin by gavage， and the control group and the model group were given saline of the same volume by gavage. After six-week treatment，the rats were sacrificed. The levels of 24-hour urine protein were measured before establishment，after four-week injection and after six-week treatment. The ratserum was collected，and the contents of serum creatinine(SCr) and blood urea nitrogen(BUN) were measured. After renal section and HE staining，the pathological changes of the kidney were observed. The expression levels of mRNA of NF- κB p65 and monocyte chemoattractant protein- 1(MCP- 1) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results：After six-week treatment，compared with those in the control group，in the model group，the level of 24- hour urine protein and the contents of SCr and BUN in serum were significantly increased； there were significant proliferation of mesangial matrix and cells in the kidney tissue；the expression levels of mRNA of NF- κB p65 and MCP- 1 were significantly increased；differences being significant(P＜0.05). Compared with those in the model group，in the extract of Radix Polygoni Multiflori group and the Lotensin group，the levels of 24- hour urine protein and the contents of SCr and BUN in serum were significantly decreased； the degree of pathological changes of the kidney tissue was decreased； the expression levels of mRNA of NF- κB p65 and MCP- 1 were significantly decreased；differences being significant(P＜0.05).Conclusion： Extract of Radix Polygoni Multiflori has certain curative effect on MsPGN rats， and its interruption on the activation of NF-κB may be one of its mechanisms.