When there is a small amount of vaginal bleeding in the cervical cavity or vaginal wall of the patient, the blood stays in the patient’s vagina for a long time and turns black after oxidation and coagulation. The black blood mixed with the patient’s leukorrhea will appear as brown leukorrhea. In this case, the patient must undergo a gynecological examination to observe where the bleeding is coming from and to see if there are any organic lesions in the cervix and vagina. 2. Consider that the black material discharged from the patient’s vagina is drug residue, which mostly occurs after the patient has vaginal or cervical inflammation and uses brown or red vaginal medication. It takes 1-2 days for the drug residue to be cleared. After it is cleared, the patient’s leucorrhea will return to normal and the patient will not need any treatment.