The umbilical cord is tied after the birth of a newborn. If the umbilical cord is sterilized in a standardized manner, the ligated umbilical cord usually falls off in 3~7 days after birth. However, there are some individual differences in the time for the umbilical cord to fall off. In most cases, the umbilical cord falls off within one to two weeks, while in some cases it may take two to three weeks to fall off, but not more than one month at the latest. Some newborns have a late umbilical cord, which may be related to the following factors. For example, the umbilical cord of newborns is thicker, and the ligature is not very tight when tying the umbilical cord, not completely blocking the blood supply of the umbilical cord, so the stump of the umbilical cord is not easy to be necrotic and fall off. If this happens, parents should take their children to the hospital for consultation, so that the surgeon can treat the cord again. In some cases, the umbilical cord falls off late because there is some secretion from the umbilical cord and the parents do not do a good job of cleaning up the area, so that the local secretion and some blood stains are tightly connected to the ligated umbilical cord. In this case, we only need to disinfect the root of the ligated umbilical cord with iodine vapour or alcohol, and clean up the secretion and the blood stains, and the umbilical cord will fall off very soon. Of course, there are also some pathological conditions, such as hypothyroidism, which may delay the cord from falling off, but they are generally rare. Umbilical cord detachment in newborns is a natural process, and a good routine disinfection before the cord is detached will promote early detachment of the umbilical cord.