The decayed upper teeth of one and a half week old baby are considered to be cavities, which are often referred to as tooth decay and worm teeth. This situation is mostly related to the baby’s improper daily diet structure and lack of good oral hygiene, at the same time, the poor development of tooth enamel may also make the baby more prone to dental caries. When tooth decay occurs, it is recommended to consult a dentist and do a good job of oral health care in general.1. Daily life attention: one and a half weeks baby’s upper teeth decay, usually should pay attention to supplement vitamin D, to avoid vitamin D deficiency and lead to future dental dysplasia. Parents should control the intake of high sugar food of baby and should not add extra sugar in supplementary food, and pay attention to clean mouth, brush teeth every morning and evening, and do not eat milk at night, so as to avoid tooth decay as much as possible; 2, stomatology treatment: now that tooth decay has appeared, only controlling diet and cleaning mouth are not enough, and need to take baby to dental clinic in time. A week and a half baby can be treated with local anesthesia under restraint or consider general anesthesia treatment according to the situation, simple caries is treated by filling, if it has caused pulpitis or periapical inflammation, root canal treatment is needed.