Reactive oxygen species (ROS) are produced under oxidative stress, such as high oxygen concentration and during the metabolic consumption of oxygen molecules. Male reproductive tissues appear to be continuously exposed to ROS produced by active metabolism. In addition, spermatozoa must pass through a high oxygen environment during the mating process. Thus, to maintain viable reproductive ability, a protective mechanism against oxidative stress is of importance. Here, we overview our current understanding of the cooperative function of antioxidative and redox systems that are involved in male fertility. Superoxide dismutase and glutathione peroxidase are major enzymes that scavenge harmful ROS in male reproductive organs. In turn, glutathione and thioredoxin systems constitute the main redox systems that repair oxidized and damaged molecules and also play a role in regulating a variety of cellular functions. While glutathione functions as an antioxidant by donating electrons to glutathione peroxidase and Reactive oxygen species (ROS) are produced under oxidative stress, such as high oxygen concentration and during the metabolic consumption of oxygen molecules. Male reproductive tissues appear to be sold exposed to ROS produced by active metabolism. Here, we overview our current understanding of the cooperative function of antioxidative and redox systems that are involved in male fertility. Superoxide dismutase And glutathione peroxidase are major enzymes that scavenge harmful ROS in male reproductive organs. In turn, glutathione and thioredoxin systems constitute the main redox systems that repair oxidized and damaged molecules and also play a role in regulating a variety of cellular functions. While glutathione functions as an antioxidant by donating electrons to glutathi one peroxidase and