Objective To investigate the expression of ubiquitin specific peptidase 7 (USP7) in the sperm of infertile man suffering asthenozoospermia or oligoasthenozoospermia, and to explore its role in the pathogenesis of male infertility. Methods The semen samples were obtained from 120 donors attending the Fertility Clinic, the Centre of Reproductive Medicine, the Second Affiliated Hospital, Chongqing Medical University. The sperm specimens were divided into normozoospermia group (n=57), asthenozoospermia group (n=37) or oligoasthenozoospermia group (n=26) after semen analysis according to 2010 WHO standards. The localization and expression of USP7 were examined using immunofluorescence and Western blotting analysis in the three groups. Then the correlation between USP7 expression and sperm parameters was analyzed. Results USP7 mainly localized in the middle part and main part of the sperm tail; the USP expression was significantly lower in asthenozoospermia group(0.86±0.53) and oligoasthenozoospermia group (0.62±0.43)compared with normozoospermia group (1.63±0.76, P<0.01). And USP7 expression was found positively correlated with the ratio of sperm moving forward(r=0.431 2, P=0.008 7), total motility rate(r=0.443 8, P=0.006 7), and sperm concentration(r=0.455 0, P=0.005 3). Conclusion The lowered expression of USP7 is related to the reduction of human sperm motility and concentration, indicating that USP7 expression may serve as an indicator for sperm quality evaluation in infertile men.