The darkening of the face after photorejuvenation may be caused by normal phenomena, melanin rebound, too much trauma and other factors. 1. Normal phenomenon: photorejuvenation is mainly the use of specific broad-spectrum color light, the local skin irradiation, penetrate to the deep skin, selective to the subcutaneous pigment or blood vessels to break down the pigmentation, and at the same time, stimulate the subcutaneous collagen proliferation. After photorejuvenation, the melanin cells in the patient’s face will be destroyed, and these dead cells will gradually rise to the surface layer of the skin, making the skin look darker, so the patient will feel the symptom of darkening of the face. 2. Melanin rebound: If the patient after photorejuvenation, the local melanin has been significantly lightened, and the skin has been completely restored. However, if patients do not do a good job of daily care, often in the ultraviolet radiation, which will make the local melanin gradually rebound, melanin deposits, resulting in black face. 3. Too much trauma: In photorejuvenation, it is very important to control the dosage of color light, if the dosage is too large in photorejuvenation, this may lead to excessive trauma to the local skin tissues, which will make the melanin cells in the base of the skin to gather, so that the patients appear photorejuvenation face black after the situation. When patients appear photorejuvenation face black, need to go to the hospital in a timely manner for a comprehensive examination, clear cause of the symptomatic treatment.