Precocious puberty is a common pediatric endocrine disorder in which children exhibit sexual characteristics that do not correspond to their actual age. It mainly refers to the appearance of secondary sexual characteristics in boys before the age of 9 and in girls before the age of 8 or the onset of menstruation before the age of 10. The specific clinical manifestations of precocious puberty are as follows: 1. The secondary sexual characteristics appear early, but the pattern of sexual characteristics development is the same as that of normal puberty development. In female patients, breasts develop first, then pubic hair and external genitalia develop, and menarche occurs mostly 2 years after breasts begin to develop. Male patients start to have enlarged penis and testicles, and then pubic hair development, often 2 years after the testicles start to enlarge, voice change and seminal emission. 2. Both boys and girls have rapid growth in height and weight during sexual development, and accelerated skeletal maturation, which will affect the final height due to premature epiphyseal fusion. 3. There may be bone age overage, but there is no diagnostic specificity. Precocious puberty in children has certain harmful effects. Parents should go to the hospital promptly if they find that school-age children have early development of secondary sexual characteristics, girls within 10 years of age have menarche, the rate of height growth is significantly faster, and the child’s growth rate is faster than normal by more than 6cm per year.