Dermatology Diseases characterized by skin pigmentation are collectively referred to as skin hyperpigmentation diseases. The pathogenesis of this group of diseases is no more than the increase in the number of melanocytes or their increased activity. From the etiology can be divided into hereditary (freckles), endocrine (chloasma), metabolic (Riel melanosis), drug (fixed drug rash), inflammatory (sunburn), neoplasm (color ), physical (friction blackening) and artificial (text). The above-mentioned tumor-related diseases are caused by an abnormal increase in the number of melanocytes, and most of them are caused by abnormal metabolism of melanocytes. The laser therapeutic apparatus uses its powerful instantaneous power, highly concentrated radiant energy and pigment selectivity, and extremely short pulse width, so that the laser energy concentrates on the pigment particles, directly vaporizes or crushes them, and is excreted through the lymphatic tissue. Without affecting the surrounding normal tissues, it achieves good results with no curative effect, no damage, no scar, little pain and safe and simple treatment.