The closing time of infant’s fontanel is about 1-1.5 years old, but there are some individual differences. The fontanelle is located at the top of the skull and is rhombic in shape, with the midpoint of the two opposite sides being about 1-1.5 cm away from the line. before birth, the skull is not fully developed and the sutures are widely spaced, forming a gap that is mainly replaced by a fibrous connective tissue septum. With growth and development, bone tissue will gradually replace this septum, and the fontanelle can gradually begin to close around 6 months of age, and around 1-1.5 years of age, the fontanelle will completely close. However, if the child has intracranial lesions, such as tumors and hydrocephalus, which increase the intracranial pressure, the fontanelle will take longer to close or even not heal, and rickets will also delay the closing of the fontanelle, and the child will have night terrors, irritability, excessive sweating and other abnormalities. Parents are advised to observe the closing of fontanelle in daily life, and if abnormal closing or symptoms occur, go to the pediatrician of the hospital in time to actively find the cause.