The relationship between IL-17 and male infertility was investigated. Seminal fluid from 57 males, including infertile and normal, were selected and subjected to routine analysis and determination of the levels of cytokines. IL-17 can be detected in seminal fluid, with concentrations from 0.45 to 16.67 pg/ml. Semen analysis showed that semen samples with low activity sperms have higher IL-17 level, while IL-17 levels have no significant influence on sperm densities, morphologies and pH values. Sperm mortality rate of low IL-17 level samples is remarkably lower than that of high IL-17 level samples. Correlation analysis indicates that seminal fluid IL-17 and IL-6, IL-8, TNF-alpha were positively correlated, and seminal IL-17 level has no effects on bacteria colony counts and serum FSH, LH, T levels. Results indicate that IL-17 may play important roles in male reproduction.