Semen liquefaction refers to the change of the state of semen from gel-like to watery, and is caused by the interaction of prostate-specific antigen with seminal vesicle coagulation protein, fibronectin, and epididymal protease inhibitors, which affect the liquefaction mechanism. Semen is mainly secreted by the seminal vesicles and prostate, with the former accounting for 60% to 70%, the latter for 20% to 30%, and the remaining 5% to 10% coming from the epididymis, urethral bulbourethral glands, and paraurethral glands. The process of coagulation and liquefaction of semen is accomplished by the secretions of prostate and seminal vesicles. Coagulation of semen is caused by coagulation factors produced by seminal vesicles, while liquefaction of semen is caused by liquefaction factors such as proteolytic enzymes produced by prostate. Tissue plasminogen activator (tPA) digests and dissolves fibrin-like material to activate plasminogen, which in turn produces fibrinolytic enzymes that help liquefy semen clots. Other factors involved in semen liquefaction include salivary acid transferase, α-amylase, pancreatic kininogenin, chymotrypsin, aminopeptidase, hyaluronidase, trypsin, collagenase-like enzyme, and lysozyme, among others. To summarize, if semen abnormality occurs, you should seek medical treatment in time.