Object To observe the effect of Guizhi Fuling Capsule (GFC) on prostatic hyperplasia in rats induced by testosterone propionate. Methods Seven days after the male rats were castrated, testosterone propionate (3 mg/kg) was sc injected in rats. Meanwhile, the rats were administered GFC (2.16, 1.08, 0.54 g/kg) once a day, and the treatment continued for 30 d. An hour after the final administration, the rats were put to death, and the weight and volume of prostates were measured. The construction of prostate cells was also observed under light microscope. Results In the GFC group, the weight and volume of prostate was significantly decreased compared with that in the model group (P0 05, 0.01). The atrophy of the prostatic gland was found under the microscope in the GFC group (P0 05, 0.01). The epithelial cell height was lower than model group, with the significance of large and middle dose groups. Conclusion GFC can inhibit prostatic hyperplasia in rats significantly.