Male semen with rotten egg odor is mainly considered to be related to reproductive system infection, urinary system infection and other factors. 1. Reproductive system infection: male semen is composed of sperm, seminal vesicle gland fluid, prostate fluid and so on. If a man has prostatitis, seminal vesicle adenitis and other diseases, it may affect the quality of semen and cause semen to have a rotten egg odor. 2. Urinary system infections: diseases such as urethritis can cause the urethral mucosa to secrete some inflammatory secretions. When ejaculating, the semen mixes with the inflammatory secretions, and the phenomenon of semen having a rotten egg odor may also occur. 3. other factors: such as urethral tumors and other diseases, may lead to some purulent secretions from the affected area, after mixing the semen, there may be a phenomenon of semen with a rotten egg smell. Male semen with rotten egg odor appears this phenomenon, the etiology is complex. It is important to pay attention to it and go to the hospital in time for relevant examinations to clarify the specific causes and follow the doctor’s instructions for treatment.