Under normal circumstances, two and a half year old baby’s tongue should be relatively thin and red, if the tongue is white, usually suggests the following situations: First, pay attention to whether the child has a poor diet or gastrointestinal cold caused by acute gastroenteritis, poor digestion caused by the tongue white. Second, we should pay attention to whether the child has malnutrition, weak spleen and stomach function, poor absorption and so on. Third, if the tongue coating is always white, it usually may suggest that the child has chronic digestive diseases, such as chronic food allergies, lactose intolerance, or chronic infectious diseases, such as inflammatory bowel disease, chronic recurrent respiratory infections, etc., it is easy to have poor digestion and thick white tongue coating.