Abstract： Objective： To discuss the curative effect of modified Buyang Huanwu tang on rats with membranous nephropathy(MN) and its possible mechanism. Methods：A total of 36 male SD rats were randomly divided into the normal group， the model group， the benazepril hydrochloride group， the modified Buyang Huanwu tang groups of high- dose， medium- dose and low- dose(the Chinese herbal medicine groups of high- dose，medium- dose and low- dose)，6 rats in each group. The normal group was injected with 6 mL/kg of saline through tail vein，and the other five groups were injected with 6 mL/kg of Anti- Fx1A to establish MN models. After successful modeling，the normal group and the model group were given 10 mL/kg of 0.9% sodium chloride injection by gavage daily，and the benazepril hydrochloride group was given 0.16 mg/mL of benazepril hydrochloride solution at a dose of 1.60 mg/kg；the Chinese herbal medicine groups of high-dose， medium- dose and low- dose were respectively given 7.04， 3.52 and 1.76 g/mL concentrated solution of Chinese herbal medicine by gavage. Before establish models，after models were successfully established and on the 7th，14th and 28th day after gastric perfusion respectively，the 24-hour urine in each group was used to detect the 24-hour urine protein(24 hUP). After 28-day administration，the rats were sacrificed；their blood was taken from the heart to detect the levels of albumin (Alb)，total cholesterol(TC)，triglyceride(TG)，serum creatinine(SCr) and blood urea nitrogen(BUN)；their kidney tissues were given hematoxylin- eosin staining(HE staining) ， Masson trichrome staining(Masson staining) and Periodic Schiff- Methenamine staining(PASM staining)， and the pathological changes in the kidney tissues were observed under optical microscope； the positive expression of immunoglobulin G(IgG) and complement C3 in the glomerulus was detected by immunofluorescence；the positive expression of podocin of podocyte slit diaphragm protein in the glomerulus was observed by immunohistochemistry；the mRNA expression of podocin and nephrin of podocyte slit diaphragm protein was detected by RT- PCR. Results： Compared with those in the normal group， in the model group， the 24 hUP was increased(P＜0.05)； subcutaneous immune complexes were formed on the basement of glomerulus；the expression of IgG and C3 increased，as well as the protein expression of podocin and the mRNA expression of podocin and nephrin in the kidney tissues were decreased(P＜0.01). Compared with those in the model group，in the four administration groups，the 24 hUP after 28-day treatment was decreased(P＜0.05)；the formation of epithelial immune complexes and the expression of IgG and C3 were decreased； the mRNA expression of podocin and nephrin in the kidney tissues was increased(P＜0.01)； the protein expression of podocin was increased， but only the difference in the Chinese herbal medicine group of high- dose was significant(P＜0.05). After 28-day administration，there was no significant difference being found in the comparison of the 24 hUP and the protein expression of podocin in the kidney tissues in the Chinese herbal medicine groups of low- dose and medium-dose. Compared with those in the benazepril hydrochloride group，the mRNA expression of podocin and nephrin in the Chinese herbal medicine group of low-dose was lower(P＜0.01)；the mRNA expression of nephrin in the Chinese herbal medicine group of medium-dose was lower(P＜0.05)，and the mRNA expression of podocin was decreased，but there being no significance in the difference. After 28- day administration，in the Chinese herbal medicine group of high- dose，the 24 hUP， the formation of epithelial immune complexes and the expression of IgG and C3 were decreased； the protein expression of podocin and the mRNA expression of podocin and nephrin were increased； differences being significant(P＜ 0.05， P＜0.01). Compared the levels of Alb， TG， TC， SCr and BUN in blood between each two groups， there being no significance in the difference. Conclusion：The modified Buyang Huanwu tang can reduce the 24 hUP of MN rats，and the high-dose one has the best effect. Its mechanism may be up-regulating the mRNA expression of prodocin and nephrin and reducing the formation of immune complexes，so that it can treat MN.