OBJECTIVE To study the semen quality of male infertility patients in Suzhou area, China. METHODS We detected the semen quality of 2 640 infertility patients in Suzhou area using computer-assisted semen analysis technology. RESULTS Of the 2 640 semen samples, 27.35% were found normal in all seminal indexes, 47.35% (1 250/2 640) abnormal in the percentage of grade a + b sperm, and 42.39% (1 119/2 640) abnormal in sperm motility. The percentage of grade a + b sperm and sperm motility were decreased with the increase of age, more obviously in those over 40 years. The incidences of asthenospermia and oligospermia were 37.31% (985/2 640) and 8.94% (236/2 640), rising with the increase of age, especially in those older than 30 years. The 9 sperm motion parameters, including VSL, VCL, LIN, MAD, VAP, STR, WOB, ALH and BCF, were significantly reduced with the decrease of sperm motility and sperm concentration. CONCLUSIONS The infertile men in Suzhou area are mainly characterized by a decrease in sperm motility, especially in the percentage of grade a + b sperm. The correlation of age with sperm motility and incidence of asthenospermia and oligospermia suggests that men also have an appropriate childbearing age.