Objective：To explore the pathogenesis and clinical treatment of chronic prostatitis（CP） by establishing chronic prostatitis rat model and observing their ethological changes. Methods：A total of 50 male Sprague Dawley rats were randomly divided into 6 groups：normal control group（n=10），45 d model group（n=10），60 d model group（n=10），90 d model group（n=10），treatment 15 d group（n=5） and treatment 45 d group（n=5）. The CP rat models were made in the latter five groups by intraperitoneal injection of 0.5 ml pertussis diphtheria tetanus（PDT） vaccine and abdominal subcutaneous multiple points injection of 1.0 ml Freund’s complete adjuvant（FCA） and 35 g/L prostate protein purification fluid at the 0 and 30th d. From the 46th d，the rats in treatment 15 d group and the treatment 45 d group were given intragastric injection of saline containing 10 mg/（kg·d） Escitalopram Oxalate tablets for continuous 15 d and 45 d respectively. The ethological change was determined by open-field test and sucrose consumption test；the morphological change of prostatic tissue was observed by light microscopy. Results：All 50 rats were involved in the result analysis. The horizontal movement，vertical movement times of open-field test and sucrose consumption were significantly decreased in 90 d model group than in normal control group[（47.40±17.45），（5.90±2.80） and （53.80±16.29） ml/24 h vs. （70.40±10.35），（12.80±4.69） and （88.21±21.66） ml/24 h] （P=0.017，P=0.038，P=0.048）. There was no significant difference in the above indicators among 45 d model group，60 d model group，treatment 15 d group and treatment 45 d group（P >0.05）. Conclusions：90 d CP model rats exhibits characteristics of depression. Escitalopram can reduce the prostatic inflammatory responses and depressive behaviors of rats with CP.