The possibility of precocious puberty should be considered when a girl’s breasts develop abnormally at the age of eight, which can be categorized as central and peripheral, and is associated with hypothalamic-pituitary-gonadal axis function, central nervous system abnormalities, and other disorders. Under normal circumstances, female breasts should develop at the age of 9~11 years old, so breast development at the age of eight years old is abnormal and usually requires a high degree of suspicion that precocious puberty may be occurring. Precocious puberty is a common endocrine disease in children’s growth and development, and can be clinically divided into central precocious puberty and peripheral precocious puberty. Studies have shown that central precocious puberty is mainly related to premature secretion of the hypothalamic-pituitary-gonadal axis and abnormalities of the central nervous system, including central nervous system infections and optic septal hypoplasia, etc. In addition, peripheral precocious puberty is a common endocrine disorder in children’s growth and development. Secondly, peripheral precocious puberty is often secondary to adrenal gland diseases, hepatocellular carcinoma, chorionic epithelial cell carcinoma and other diseases. Therefore, for children with breast development at the age of eight, they need to go to the hospital in time and cooperate with the doctor for active treatment, so as not to delay the condition.