Dark colored particles in the semen are considered to be present in the presence of hematospermia. It may be caused by irregular sex life, or due to seminal vesiculitis, trauma or surgery, tumors and other factors. 1. Irregular sex life: if sex life is too frequent, strenuous or long-term abstinence, due to the pressure of the seminal vesicle glands change dramatically, resulting in local microvascular rupture bleeding, at this time the semen can be accompanied by dark-colored particles. 2. Trauma or surgery: patients who have perineal or pelvic injuries, testicular injuries, etc., can lead to hematospermia, and semen can have dark-colored particles. In addition, prostate biopsy, vasectomy, etc., can also lead to temporary hematospermia, which usually recovers on its own. 3. Vesiculitis: Vesicourethral ducts are curved and have many mucosal folds, which are easy to drain poorly, when pathogenic bacteria invade, inflammation occurs, which can cause urinary pain, urinary urgency, frequent urination, urethral burning sensation and other discomforts, and there can be hematospermia, that is, the patient’s semen appears red or brown. 4. Tumor: for example, adenoma of seminal vesicle, malignant tumor of prostate and seminal vesicle may cause semen with dark particles. In addition, there may be other reasons for dark-colored semen particles, it is recommended to actively seek medical advice, under the guidance of a professional physician for diagnosis and treatment.