Objective:To explore the therapeutic effect of low-intensity extracorporeal shock wave (Li-ESW) in model rats with chronic prostatitis and its optimal parameters.Methods:From April to August 2019, 90 healthy male SD rats aged 8 weeks were randomly divided into control group (group C, n=15), model group (group M, n=15) and shock wave treatment group (group T, n=60), which were treated with Li-ESW after being modeled successfully. The rats in group T were supine and treated with focused Li-ESW, and the probe was placed above the anatomical position of the prostate. Treatment scheme was 3 Hz of frequency, 500 pulses, and once a week for 4 weeks. Group T was divided into group T1(0.09 mJ/mm 2), T2(0.20 mJ/mm 2), T3(0.30 mJ/mm 2) and T4(0.40 mJ/mm 2) according to energy flux density, with 15 rats in each group. Before the establishment of the model, the rats in each group were tested with von Frey fiber of 2 g, 4 g and 6 g at the scrotum respectively, and the positive reaction was recorded. There was no significant difference between the three groups ( P>0.05). After one week, the rat model with CP was established by injecting 3% carrageenan into the bilateral lobes of the prostate under anesthesia. And one week after the modeling was completed, the rats in each group underwent von Frey test again to measure pain and evaluate the modeling effects. Group T was then treated once a week for a 4-week period. During the treatment, von Frey test was performed before each treatment to evaluate the treatment effect of the previous week. After the von Frey test for one, two and four weeks of treatment, 5 rats were sacrificed in each group, and the bilateral lobes of the prostate were dissected under aseptic conditions for paraffin inclusion and HE staining. Result:The positive reaction in group M and each group T was significantly more than those in group C ( P<0.001) one week after the modeling was completed, and there was no significant difference between group M and group T. The number of positive reactions in group T2 was lower than that in group M at each time point after treatment ( P<0.05), and it is also less in group T1, T3 and T4 were than that in group M after 3 weeks, 3 and 4 weeks and 2 weeks respectively( P<0.05). In group T2, the number of positive reactions began to decrease after 1 week of treatment, and reached the lowest after 4 weeks, with significant difference in pain measurement results at different time points ( P<0.05). The results of pathological examination showed that there were more inflammatory cells in prostatic stroma and disordered arrangement of epithelial cells in group M than that in group C. The pathological scores of group M, T1, T2, T3 and T4 were 8, 7, 4, 6, 9 after 1 week treatment, 8, 5, 3, 4, 7 points after 2 weeks treatment, and 7, 3, 2, 4, 7 points after 4 weeks treatment, respectively. Conclusions:Low-intensity extracorporeal shock wave treatment had a significant effect on the improvement of symptoms in model rats with chronic prostatitis. Under the scheme of frequency 3 Hz, 500 pulses, once a week for 4 weeks, the optimal parameters is 0.20 mJ/mm 2.