Abstract: Objective: To probe the methods of experimental research for the drug activities of the rat prostates. Methods: With androgen and Staphylococcus aureus injected into the prostates, the bacterial prostatitis (BP) models and benign prostatic hyperplasia with bacterial prostatitis (BHP-BP) models were developed. The animals were fed with tetracycline and then the drug activities in the serum and the prostatic tissues, the quantities of the bacteria and the histopathlogical changes in the prostateic tissues were detected separately in variant times. Results: After ten days, the histopathlogical changes of the benign hyperplasia and mesenchyma could be found in the prostatic tissue from BHP animals and acute suppurative inflammation could be found in prostatic tissue from the BP group after infected for two days. The drug activities of 22.44mg/g in BP group and 20.26mg/g in BPH-BP group were found until 3.5-4hours and the values were higher than MBC of the tetracycline and the antibacterial activity of the sera at the same time. After 8 to 11 days of treating, the bacteria would not be isolated from the prostates of the animals with BP or BHP-BP and the acute or chronic inflammation histopathlogical change did not be found in the prostates of animals with BP. 30 CFU of bacteria could be found in per gram tissue of prostate and both of the acute and chronic suppurative inflammation could be found in the BP group without treatment at the 28 days afterinfected. Conclusion: The tetracycline activities in the prostates of rats with BP or BPH-BP will be same as or even higher than that of serum and the MBC of the drug. The quantity of sensitive bacteria in prostates will be diminished and disappeared during treatment.