It is the most common benign epidermal proliferative tumor in the elderly, the cause of which is unknown and may be related to sun exposure and chronic inflammatory stimulation. They start as pale brown macules or flat papules with a smooth or slightly papillomatous surface, increasing in number with age, with a diameter of 1 mm to 25 px or several centimeters, with clear borders and a papillomatous surface and greasy scabs, which are easily scraped off. Some of the damage can be very dramatically pigmented, dark brown or black, and the color of the old damage is highly variable and can be normal skin color, light brown, dark brown or black. The disease can be solitary, but is usually multifocal and is mostly asymptomatic, with occasional itching. The lesions are slow to develop and rarely become malignant. In the same area will also appear another “spot” – light keratosis or called senile keratosis, the initial skin-colored or light red flat papules or small nodules, rice grain to bean size; over time transformed into yellow-brown or black-brown, the surface has dry keratinous crust, not easy to peel off, forcible peeling very easy to bleed. Sunlight, ultraviolet light, radioactive heat, as well as asphalt or coal and its extracts are prone to induce this disease. Since most of the disease has no conscious symptoms, it is easily overlooked. However, it is recognized as a pre-cancerous skin lesion with a 20% cancer rate. When the lesion is combined with inflammation, erosion and ulceration, it is a sign of secondary squamous carcinoma. However, to determine whether there is cancer, skin pathology biopsy should be performed. Early treatment is essential to prevent the deterioration of the disease. Commonly used treatments include cryotherapy, photodynamic therapy, laser, topical retinoic acid, surgical excision, etc.