【Abstract】Objective To observe the changes of mechanical pain thresholds and autophagy related proteins microtubule-associated protein 1 light chain 3 ( LC3 ) and sequestosome 1( SQSTM1 also known as p62 ) expression levels in the C57BL/6 mice model of chronic prostatitis/ chronic pelvic pain syndrome(CP/CPPS), then offer animal experimental evidences for CP/CPPS pain and autophagy behavior study. Methods 36 male C57BL/6 mice were divided into three groups randomly and averagely, including model group, control group and na飗e group. The CP/CPPS model was established by subcutaneous injection in the lower abdomen region with suspension liquid. The suspension liquid contained protein extract of male SD rat prostate glands and complete freund adjuvant (CFA). At 1month and 6 months after modeling, mice were sacrificed and prostate tissues were harvested for detection of histological changes using HE stain. Mechanical tactile hyperalgesia was measured with Von Frey Filaments. And we detected the autophagy related proteins LC3 and p62 expression levels in prostate tissue by immunohistochemical stain respectively. The average IOD was measured by Image Pro Plus 6.0，and the data statistical analysis was performed with GraphPad Prism 5 software. Results HE staining results showed the appearance of chronic prostatitis in model group. The chronic prostatitis represented as different degrees of hyperplasia and lymphocytic infiltration and last for 6 months after modeling. Moreover the prostate intraepithelial neoplasia( PIN ) appeared in model group at 6 months after modeling, characterd with the disappearence of basement membrane and obvious abnormity of nucleus. While control and na飗e group showed normal histology from 1month to 6 months. Compared with control and na飗e group, the mechanical pain thresholds in the model group were significantly decreased with timing from(0.353?0.154)g at 0 week to (0.008?0.00) g at 22 weeks, p<0.05. The immunohistochemical results suggested there was a increase in the expression levels of autophagy related proteins LC3 and p62 in the prostate tissues in model mice. The average IOD of model group increase significantly with timing from (2.767?0.464; 2.872?1.642)% at 1month to (13.501?1.900; 9.07?0.49)% at 6 month when compared with control and na飗e group (P< 0.05). Conclusion CP/CPPS model was successfully established in C57BL/6 mice. For model group, the mechanical pain threshold decreased and autophagy levels increased gradually with timing, these phenomena showed that chronic inflammation microenvironment could promote pain and autophagy activity in prostate, which was closely related with the occurrence and development of prostate intraepithelial neoplasia and prostate cancer.