The blackened semen is generally considered to be hematospermia, which may be caused by orchitis, epididymitis, prostatitis, trauma and other diseases. 1. Testiculitis: Testiculitis is an infectious disease caused by pathogen infection, which is contagious and may be transmitted through sexual contact, and after the disease, it will lead to the patient’s testicles appearing enlarged as well as pain and other symptoms, and it may also cause the quality of sperm to cause semen to be dark. 2. Epididymitis: Epididymitis is caused by bacterial infection, and may also be caused by urine reflux, when the vas deferens obstruction will also trigger epididymitis, which will lead to epididymitis pain, swelling and other symptoms, when the epididymitis part of the swelling will affect the secretion of sperms caused by the darkness of the semen. 3. prostatitis: mainly prostatitis due to some specific bacterial infections caused by reproductive system complications, when these parts of the inflammation will lead to local mucous membrane congestion and edema, iron oxidation in the blood looks like semen black. 4. trauma: may be trauma caused by bleeding symptoms within the urinary system, causing semen color black. The blackened semen may also be the result of diseases such as seminal vesiculitis or prostatitis, which need to go to the hospital to determine the targeted treatment.