Objective:To investigate the effect of hydrogen-rich Korean Red Ginseng (KRG) water (HRGW) mixture on the spermatogenesis and sperm motility of mice of different ages.Methods:Eighty young (3 month-old) and aged (12 month-old) male mice were randomly assigned to 4 groups (n=10 per group) including control group,hydrogen-rich water (HRW) group (10 mL/kg daily),KRG group (50 mg/kg daily) and HRGW group (10 mL/kg and 50 mg/kg daily) by an oral zoned needle for 4 weeks.Sperm count and motility were measured using sperm suspension released from cauda epididymis.Serum follicle stimulating hormone (FSH),luteinizing hormone (LH),testosterone,and reactive oxygen species (ROS) in serum have also been estimated.Tubular changes were examined through histological hematoxylin and eosin staining.Expression of antioxidation (PPx3,PPx4,GSTm5 and GPx4),spermatogenesis (inhibin-α,neptin-2 and CREM),antiaging (SIRT1 and SIRT2),and angiogenesis [visfatin and vascular endothelial growth factor (VEGF)] related genes were examined through real-time polymerase chain reaction.Results:HRW and KRG treatment stimulated spermatogenesis followed by increasing sperm production and sperm motility (P＜0.05).These effects were strengthened synergistically by a HRGW mixture (P＜0.05 or P＜0.01).HRGW greatly increased the expressions of antioxidation,antiaging,spermatogenesis related genes and VEGF especially in aged mice (P＜0.05).Serum testosterone and FSH levels also increased,while serum ROS level decreased (all P＜0.05).Conclusion:HRGW increases sperm production and motility by enhancing antioxidation and stimulating spermatogenesis and sex hormone production,particularly in aged mice.