Abstract: Objective To investigate the influence of male reproductive system infection on semen quality and male infertility. Methods Three hundred and twenty-eight male infertile patients with previously or currently reproductive system infection were selected,Among them 140 patients were infected with Ureaplasma urealyticum 93 with Chlamydia trachomatis,41 with cytomegalovirus,and 54 with mumps virus. The control group was 230 healthy men with reproductive history,perform semen quality analysis on the semen samples of the subjects above. Results Compared with the control group,the sperm density and living rate of the infection group were significantly decreased （P<0.05）,sperm malformation rate was significantly higher（P<0.05）,and the semen volume,semen liquefaction time and pH value and other parameters were not statistically significant difference（P>0.05）. Conclusion Male reproductive system infection can lead to a decline in semen quality,affecting male fertility.

Key words: Reproductive system infection, Semen quality, Male infertility