Children’s mouth inside rotten has three original factors caused by: first, oral ulcers; second, suffered from herpes stomatitis; third, suffered from fungal stomatitis. Children with ulcers inside the mouth parents should let children drink more water, eat more fresh vegetables and fruits to supplement vitamin C, you can spray watermelon cream spray on the surface of the ulcer to promote the healing of the ulcer. Children with herpetic stomatitis, which begins with small blisters in the mouth that break down and leave an erosion, can be treated with topical antiviral medications such as acyclovir ointment. If the child has a fungal infection in the mouth, parents can let the child gargle with aqueous sodium bicarbonate solution, or grind the mycotoxin tablets into powder and apply it to the child’s mouth, both of which are able to treat fungal infections in the mouth.