According to a comprehensive report by Danish scientist Carlsen in 1992, sperm density in men worldwide has halved in the last 50 years, with an average annual decline of 1%. Male fertility is declining day by day, and to understand what conditions ejaculate the best quality sperm, it is first important to know that sperm production and maturation do not happen overnight, and it usually takes nearly 3 months to complete such a cycle. Therefore, to have high quality sperm, you need to live a regular life for a long time and avoid the influence of some unfavorable factors. Having a successful career but a busier work schedule, smoking, drinking, socializing plus great work pressure are all big problems that affect semen quality. Heavy smoking can lead to lower sperm count and motility, as well as damage to sperm DNA, which may cause congenital defects and genetic defects in the offspring. For non-smokers, it is also important to avoid inhaling too much second-hand smoke. Excessive alcohol can directly damage the testicles, leading to decreased spermatogenesis and impaired sperm maturation. On the other hand, according to research data, being in a crowded, annoying, noisy environment, or being in a long-term psychological state of excessive fatigue and tension and excitement can cause degenerative changes in the testes and affect fertility. Among them, psychological stress and tension affect reproduction mainly through their effects on the neuroendocrine system. In addition to work pressure, sexual disharmony and prolonged infertility is also a major cause of excessive psychological stress in men, which is one of the reasons why many people are bent on fertility but never as well as they should be. Therefore, more attention needs to be paid to the above aspects. First of all, choose looser pants for Mr. Tao, because wearing too tight underwear and jeans can make the scrotum, testicles and epididymis temperature rise and affect the production and maturation of sperm. At the same time, too many hot baths and saunas can also have a negative impact. Second, pay attention to the change of diet structure. Eat more high-quality proteins and supplement amino acids, especially arginine, which is important for sperm production. Chinese yam, eel, sea cucumber, crab, black fish, tofu skin, walnuts, sesame, etc. all contain more arginine. And trace elements also play a vital role in male reproduction. Studies have shown that a lack of zinc in the human body can lead to a decrease in the number of sperm, an increase in deformed sperm and a decrease in sexual function. Therefore, the diet should be appropriate to include millet, corn, sweet potatoes, soybeans, pumpkin and seafood oysters and other foods that contain more zinc; selenium has a great role in sperm production and maintaining the stability of the sperm structure, etc. Foods with high selenium content are mainly jellyfish skin, kelp, cuttlefish, clams, seafood such as nori. Vitamins A, B, C, and E are important for providing raw materials for sperm and semen, promoting sperm production, and enhancing sperm vitality, and are also important substances that are indispensable for maintaining the entire metabolic process of sperm. They are mainly found in animal livers, vegetable oils, green leafy vegetables and carrots, peas, tomatoes, lentils, pumpkins, potatoes, dates and fresh fruits. In addition to the above points, the deteriorating environmental problems, is also one of the important factors affecting the quality of male semen, need to consciously avoid a variety of organic substances, such as benzene, formaldehyde, food additives and pesticides; and car exhaust, electromagnetic waves and various types of radiation are human sperm killers, need to pay sufficient attention to. Therefore, it is necessary to focus on the above points and be able to maintain them for a long time. Only when these points are truly achieved can we ensure that the ejaculated semen has good quality and achieve the purpose of eugenics and fertility.