Semen exists in the genital tract in a liquid state. When semen is ejaculated from the penile orifice, it immediately turns into a jelly-like or clot-like milky white substance, at which time the spermatozoa are contained within the semen or attached to the surface and cannot swim freely. After 5 to 45 minutes, the semen produces an automatic liquefaction process that liquefies the gel and turns it into a thin, flowing liquid. This coagulation and liquefaction process is an enzyme-catalyzed process. A protein-like substance secreted by the seminal vesicle gland forms the matrix for the formation of the gel-like substance, while a fibrin hydrolase secreted by the prostate gland is involved in the liquefaction process, and this enzyme also dissolves the self-clotting mass. A liquefaction factor with a molecular weight of 33,000 has been isolated from semen. This liquid-agglutination-liquefaction process of semen has some physiological significance. The liquid state at the beginning is to facilitate the ejection of semen. The subsequent formation of clots facilitates the stay of semen in the vagina for a longer period of time and allows the sperm to rest and gain energy. Once liquefied, the sperm has enough energy to penetrate the cervical mucus and continue to push deeper into the reproductive tract, eventually reaching the fallopian tubes. In rodents, such as rats, which have coagulation glands, semen immediately coagulates when ejaculated to form a vaginal plug. It completely seals the semen in the vagina before the vaginal pessary falls off on its own the next day. When inflammation occurs in the prostate or seminal vesicle glands, the lack or destruction of the secretion of protein hydrolase causes a dysregulation of the enzyme system, making the semen in some patients not liquefy even when left for one hour, or incomplete liquefaction and too viscous. This is called semen non-liquefaction and is a pathological phenomenon. In this case, the sperm cannot move, which naturally causes infertility. Therefore, diseases of the seminal vesicles and prostate gland are important causes of non-liquefaction. The diagnosis of semen non-liquefaction is relatively easy to make by observing the changes in the properties of fresh semen, and it is not difficult to make a correct judgment even by the patient himself. The important thing is to find out further the cause of the non-liquefaction. There are several methods to treat semen non-liquefaction as follows: (1) Thorough treatment of primary lesions such as prostatitis and seminal vesicle adenitis to restore their normal function. (2) Rinse the vagina with saline containing 4% amylase before sexual intercourse or inject 1 ml into the vagina after sexual intercourse. The enzyme can also be mixed with 50 mg of cocoa butter to make a 3 cm long plug and inserted into the vagina before intercourse. The discovery of this method was inspired by the observation that saliva has the effect of liquefying semen. Amylase not only has the ability to promote the liquefaction of semen and affect glycogen-containing vaginal or cervical secretions, but also serves as a source of energy for sperm activity. Therefore, this method has been widely used. (3) Adding seminal plasma from a normal person to semen to induce liquefaction. However, it is first necessary to make sure that this seminal plasma does not contain anti-sperm antibodies, is free of infection, and has been previously processed by high-speed centrifugation, removal of sediment and freeze-thawing 3 times. (4) The semen is ejected into a container with culture fluid and repeatedly aspirated with a syringe with an 18- or 19-gauge needle until the semen is thin, then centrifuged twice, washed, and finally the sperm is resuspended in a certain amount of culture fluid for artificial insemination. (5) If the semen is too viscous, the segmental ejaculation method can be used, leaving the first three ejaculations in the vagina, immediately withdrawing the penis and ejaculating the rest of the semen outside. Because the latter part of the semen mainly contains seminal vesicle gland secretion, it is more viscous.