Abstract: Objective: To explore the expression of Kif2a in male semen,and its effects on male infertility.Methods: Seventy semen specimens were collected and purified.The total RNA in all specimens was extracted,and transcripted into cDNA.The Kif2a mRNA was detected using fluorescence quantitative PCR.The samples were divided into abnomal semen group and normal group according to the semen parameters(including sperm survival,sperm motility and sperm density) according to the fifth edition of "Laboratory manual for human semen testing and treatment" of WHO.Results: The Kif2a mRNA expression level in normal sperm survival and sperm vitality group was 7.54 times of abnormal group,and the difference of which was statistically significant(P<0.05).The difference of the Kif2a mRNA expression level between normal and abnormal sperm density group was not statistically significant(P>0.05).Conclusions: The low sperm motility and survival rate may be due to the low expression of Kif2a in spermatogonial cells caused by sperm cells spindle failing to form,which affects the pregnancy.