Brown spots on the legs may be caused by post-inflammatory hyperpigmentation, seborrheic keratosis, milk coffee spots, etc., which should be treated in time after the cause is clarified. 1. post-inflammatory hyperpigmentation: if the patient is in the legs of eczema, folliculitis after the healing of the calf long brown spots, it should be considered a temporary hyperpigmentation caused by the general need for special treatment. 2. seborrheic keratosis, a kind of benign tumor mostly seen in people over 40, patients will have brown spots on calves and other parts of the body, which can be removed by freezing, laser, surgery and other ways under the guidance of doctors. 3. Milk coffee spot: if the child is just born or born soon after the appearance of a long brown spot on the calf, should be considered to be caused by milk coffee spot, and its and the surrounding tissue boundaries are clear, generally no special treatment. The spot on the calf, should consult the doctor in time, clarify the cause of the disease, under the guidance of the physician for treatment.