The reasons for children’s fever, gums red and swollen are as follows: 1, children’s oral hygiene, poor cleaning, adhering to a large number of food residues around the crown, causing bacterial infection, resulting in localized redness, swelling and pain. 2, often chewing hard texture of the grinding stick, toys, or rubber nipples, etc., able to bruise the oral mucosa, resulting in the number of bacteria proliferated, invading the trauma to form localized redness and swelling. 3, deep caries in milk teeth caused acute Apical periodontitis attack, a large number of inflammatory secretions in the pulp cavity through the apical foramen, causing swelling of the gums, serious inflammatory substances will spread into the tissue space, triggering symptoms such as elevated temperature, need to be opened as soon as possible to drain the pulp.