Buttocks on the black black may be sedentary caused by long-term pressure or friction of the buttocks caused by regular exfoliation with scrubs to relieve, may also be caused by melanin deposition, need to go to the hospital to do laser removal, but also can be coated with medication. 1. Long-term pressure or friction on the buttocks: It is recommended that patients use chairs with soft cushions to reduce the friction of the buttock skin, can regularly use scrubs to remove the keratin on the buttock skin in the bath, use body lotion to keep the skin moist after the bath, and do not sit for a long time in normal times. 2. Melanin deposition: the best way to remove melanin deposition is laser, can through the principle of photothermal directly to the dermis pigment particles completely decomposed, in the laser surgery should be properly coated with erythromycin ointment, and do a good job of skin local cleanliness and hygiene. You can also apply local hydroquinone cream, vitamin E milk and other treatments. When this symptom occurs, if you need treatment, it is recommended to go to the hospital in time, and use drugs or other ways to intervene under the guidance of the doctor.