Fifty male SD rats were randomly divided into control group， model group， low， medium and high doses of SPE groups（ n=10）. In addition to control group， the rats in other groups were given cationic bovine serum albumin to establish the membranous nephropathy models. The rats in low， medium and high doses of SPE groups were given 1.5， 3.0 and 4.5 mg·kg^－1 SPE by gavage， and the rats in model group and control group were given the same amount of normal saline， last for 4 weeks. The levels of creatinine （Scr）， urea nitrogen （BUN） and albumin （ALB） in serum of the rats were determined. TUNEL assay was used to determine the apoptotic rates of kidney tissue cells of the rats in various groups. Real-time fluorescence quantitative PCR（RT-qPCR） and Western blotting methods were used to detect the expression levels of Bcl-2， Bax， Caspase-3 mRNA and proteins in kidney tissue.

Compared with control group， the levels of serum Scr and BUN of the rats in model group were significantly increased （P<0.05）， while the level of serum ALB was significantly decreased （P<0.05）， the expression levels of Bcl-2 mRNA and proteins in kidney tissue of the rats were significantly decreased （P<0.05）， the expression levels of Bax and Caspase-3 mRNA and proteins in kidney tissue were significantly increased（P<0.05）， and the apoptotic rates were significantly increased （P<0.05）. Compared with model group， the levels of serum Scr and BUN in low， medium and high doses of SPE groups were significantly decreased （P<0.05）， while the level of serum ALB was significantly increased （P<0.05）， the expression levels of Bcl-2 mRNA and protein and proteins in kidney tissue were significantly increased （P<0.05）， the expression level of Bax and Caspase-3 mRNA and proteins in kidney tissue were significantly increased （P<0.05），and the apoptotic rates were significantly increased （P<0.05）.Compared with low dose of SPE group， the levels of serum Scr and BUN in medium and high doses of SPE groups were significantly decreased （P<0.05），while the levels of serum ALB were significantly increased （P<0.05）， the expression levels of Bcl-2 mRNA and protein in kidney tissue were significantly increased （P<0.05）， the expression levels of Bax and Caspase-3 mRNA and proteins in kidney tissue were significantly decreased （P<0.05）， and the apoptotic rates were significantly decreased （P<0.05）.

SPE can protecte the kidney of the rats with membranous nephropathy by regulating the expression levels of Bcl-2 and Bax mRNA and proteins， and reduce the apoptosis of kidney tissue cells.