An 8 year old child with a breast nucleus is considered to have possible precocious puberty. Precocious puberty refers to the appearance of secondary sexual characteristics before the age of 8 for girls and 9 for boys. It is mainly caused by the advancement of the function of the hypothalamic-pituitary-gonadal axis, which is mainly manifested by the advancement of puberty, and in girls, it is mainly manifested by the development of breasts, the change of external genitalia, and the onset of menstruation. Boys mainly show testicular volume increase, penis growth, beard, pubic hair, axillary hair appear. Excessive body or weight gain. 8-year-old children with breast nucleus are recommended to go to the hospital for examination, and under the guidance of the doctor, targeted treatment is carried out in conjunction with their own situation. In daily life, children should be avoided to be exposed to the environment with high estrogen, do not use cosmetics too early, in addition, children may also promote the initiation of puberty if they watch television footage with pornography.