Rhesus Monkeys (Macaca mulatta) were used to provide a better benign prostate hyperplasia (BPH) model, and to explore the optimal conditions. A total of 12 male rhesus monkeys were divided into treatment and control groups at random and were administrated testosterone propionate (TP) through hypodermic injection for eight weeks after castration. Three treatment groups were given 0.8, 2.5, 7.5 mg/(kg?d) TP respectively, and the control group was given the same volume of vehicle. The prostate volumes of rhesus monkeys were measured with ultrasonic diagnosis instrument before castration, at eight weeks after castration, at four weeks and eight weeks after being given TP. Then, the serum of monkeys at all these experimental stages were separated and collected. Eight weeks later of being given TP, the rhesus monkeys were killed and the prostates were prepared. After the wet weight and volume of prostate were measured, paraffine section of BPH was stained by the H.E methods. Pictures were taken by digital camera under microscope, and all the pictures were analyzed by computer for epithelial cell height and acinar luminal area of prostate with micro image analysis soft ware. And then, the dihydrotestosterone (DHT) level of serum and prostate were detected with ELISA kit. The comparison of difference between groups was analyzed with independent-samples T test method using SPSS 13.0. The ultrasonic results showed that the prostate volumes of all the rhesus monkeys at eight weeks after castration were smaller than before castration (P < 0.05). After having been administrated TP for four weeks and for eight weeks, the prostate volumes of all treatment groups were larger than the control group (P < 0.05), and the best was mid-dose group (P < 0.01). But with TP administration for four weeks and for eight weeks, there were no significant differences between treatment groups (P > 0.05) (Table 1). The wet weights and volumes of the prostate of all treatment groups were higher than those of the control group (P < 0.05), and the maximum was mid-dose group (Table 3). The results of micro image analysis showed that the acinar luminal area and the epithelial cell height of prostate of all treatment groups were increased than the control group (P < 0.01) (Table 4, Fig. 2). The DHT level of serum (P < 0.01) and prostate (P < 0.05) of the rhesus monkeys of all treatment groups were increased than the control group, and the maximum was mid-dose group. But with TP administration for four weeks and for eight weeks, there were no significant differences between treatment groups (P > 0.05) (Table 2 and 4 ). It is practicable to establish BPH model in rhesus monkeys with TP administration. It is initially determined that the suitable conditions for the TP dose of 2.5 mg/(kg?d), and for the delivery time of 4 weeks.