Abstract : This study was conducted to investigate the effect of phenolic extract of oats seeds on parameters of sperm and reproductive organs of white male mice. Forty (40) male mice were divided equally into four groups: the first group served as a control group (DW), the rest of the groups received concentrations of (10, 20, 40 mg/kg b.wt.) of phenolic extract daily for 40 days. The results showed a significant increase (P<0.05) in sperm motility, sperm concentration and sperm viability. As for the percentage of abnormal sperms in the caudal epididymis, it decreased significantly (P<0.05) in male mice dosed with phenol extract concentrations. The current results also indicated that there were significant differences (P<0.05) in weight of testes, epididymis, and animal body weight compared to the control group. Hence we can use the seeds of the oat plant in the current study to improve the fertility of animals, including humans because of their antioxidants.