Objective: We have explored the role of nuclear factor kappa B (NF-kB) in the pathogenesis of chronic glomerulonephritis, and investigated the effect of rhododendron root on the activation of NF-kB. Methods: Thirty-six Wistar rats were randomly divided into three groups: a control group, a glomerulonephritis model group and a therapy group (glomerulonephritis animals treated with the root of rhododendron). Bovine serum albumin (BSA) nephritis was induced by subcutaneous immunization and daily intraperitoneal administration of BSA. Twenty-four-hour urinary protein and serum creatinine values were measured, and renal pathology was assessed histologically by optical microscopy and electron microscopy. NF-κB activity was determined by an electrophoretic mobility shift assay (EMSA). Results: Compared with the control rats, glomerulonephritis model rats exhibited a significant increase in both 24h urinary protein and serum creatinine, and had abnormal renal histology. The administration of the root of rhododendron ameliorated these changes. NF-κB activity in glomerulonephritis model group was greater than that in rhododendron-treated group, and NF-κB activity was greater in both glomerulonephritis groups than in the control group (P<0.01). Conclusion: These observations suggest that NF-kB plays a role in the pathogenesis of chronic glomerulonephritis, and rhododendron root may attenuate renal damages by downregulating the activation of NF-kB in this model.