Fructose secretion by the seminal vesicle gland is the main source of sperm energy; when the seminal vesicle gland is dysfunctional, the fructose content decreases, causing a decrease in sperm motility and leading to weak spermatozoa; 2, when the seminal vesicle is inflamed, incomplete ejaculation or ejaculation is too frequent, the fructose content decreases; 3, in men with bilateral ejaculatory duct obstruction, congenital seminal vesicle deficiency or poor hair, the fructose measurement is negative or extremely low; 4, the fructose content can indirectly reflect the function of testicular The level of testosterone affects the secretion of fructose in seminal vesicles, and androgen deficiency can cause a decrease in fructose content; 5, fructose combined with seminal plasma neutral alpha-glucosidase measurement can locate the site of obstruction in patients with obstructive azoospermia.