In the present study, we investigate the effects of an extract isolated from traditional Chinese medicine Zi-Shen Pill (ZSPE) on benign prostatic hyperplasia (BPH) in rats induced by testosterone after castration. A total of 50 rats were equally divided into five groups: Group 1 served as control (sham-operated group); Group 2 was model group; Group 3 and Group 4 animals were administered with ZSPE at dose levels of 300 mg/kg and 600 mg/kg; Group 5 was served as positive control group and treated with finasteride at a dose of 1 mg/kg. The drugs were administered orally once a day for 28 days consecutively. The prostate weight, prostatic index, and serum dihydrotestosterone (DHT) levels were significantly reduced and the pathological changes in BPH were also by ameliorated ZSPE. Immunohistochemical examination revealed that the expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in prostate were inhibited by ZSPE treatment, whereas the levels of transforming growth factor-beta1 (TGF-beta1) were increased. These results suggest that ZSPE has a definite inhibitory effect on BPH and might be an alternative medicine for treatment of human BPH.