Nevus of Ota is a blue, brown, black or mixed-color patch or spot distributed around the eyes. It can be manifested as brown, greenish-brown or greenish-black pigmented spots on one side of the face or both sides of the face. This disease has a family history, most nevus of ota at birth or shortly after birth, some patients are delayed, or pubertal development or postpartum, after trauma, individual patients can occur after the age of 35. But no matter when it grows, its nature is the same, there is no difference. For those patients who have nevus of ota at birth or it occurs soon after birth, it usually fluctuates once when they are around 4-5 years old and once when they are 12-14 years old, which means that it grows a little bit bigger or darker in color during this period, and it is more stable later on. For patients with nevus of ota that occurs later, they usually grow it when they are around 4-5 years old or 12-14 years old, but of course there are those who grow it much later. The color of nevus of Ota can change with seasons, such as darker color in summer and lighter color in winter, and emotions also have influence on the color. Second, exogenous hyperpigmentation is a foreign body pigmentation 1, tattoo for artificial piercing dye: often use the needle piercing method of dye into the skin, can form a variety of colors, a variety of patterns. Professional dyes are mainly cochineal, iron oxide, mercuric sulfide, methyl blue, etc., after professional processing, strong adhesion, difficult to fade or remove. Non-professional dyes are gentian violet, ink, charcoal powder, turmeric and so on. 2, explosion powder particle sedimentation disorder or foreign body tattoo caused by accidents. Tiny foreign particles flying into the skin or with trauma into the skin caused by pigmentation abnormalities. Pathogenic factors are diverse. Coal miners due to coal mining or gas explosion can cause coal dust splashed into the skin, also known as coal dust hyperpigmentation; infrastructure workers, blasting operators, accidental explosions or traffic accidents can make the mud, sand, gravel and other substances into the skin with the trauma, also known as mud and sand hyperpigmentation; explosives, explosions of gunpowder to the pigmentation, also known as gunpowder hyperpigmentation. 3.Metallic hyperpigmentation is caused by the deposition of metal particles. Is due to occupational relations long-term contact with certain metal substances or due to disease caused by the long-term application of certain metal preparations. It is absorbed into the body through blood circulation and deposited in internal organs, skin or mucous membranes, and can also be directly penetrated into the skin by external application, which makes the skin and mucous membranes colored. Generally metallic hyperpigmentation is mostly caused by gold, silver, mercury and bismuth. 1064nm laser wavelength: adapted to deep pigmented lesions and dark-colored tattoos. 1064nm has a strong penetrating ability to skin tissues and can reach melanocytes or black-blue tattoo dye particles that are in the deeper layers of the skin. Through the relative selective photothermal effect destroys and destroys melanocytes, its outstanding feature is that the treatment can be done without local anesthesia, complete a treatment within several minutes to tens of minutes, the operation is very convenient, the final result of the treatment is very ideal, the success rate is high, not only no scar, but also no change in the texture of the skin, the effect and the number of times are related to the type of nevus of ota’s pathology, although the number of times of the treatment is more, but the laser treatment is undoubtedly is the ideal choice for nevus of Ota treatment. The treatment of nevus of Ota and exogenous hyperpigmentation using laser generally requires 3-7 treatments to achieve the desired effect. The deeper the pigmentation of the lesion, the more sessions are required. Ultimately, complete healing without scarring can be achieved. No recurrence has been reported.