Black spots on the tongue of children may be caused by dietary factors, oral pigmented moles, subcutaneous bleeding, oral infections and so on. 1. Dietary factors: children may eat foods with darker pigmentation, such as mulberries, resulting in black spots on the tongue, but they will usually fade away gradually. 2. Oral pigmented nevus: it often occurs on the lateral edge of the tongue or the back of the tongue, most of the borders are clear, there are no other uncomfortable symptoms, and it belongs to benign lesions. 3. Subcutaneous hemorrhage: it may be because the tongue will not be injured, for example, biting the tongue when eating, resulting in local submucosal bleeding caused by the bruising phenomenon. 4. Oral infection: it may be caused by the dysfunction of the internal flora of the oral cavity, which leads to the infection of melanin-producing anthropomorphic bacilli. Children with black spots on the tongue, there may be other causes, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.