Breast development in eight-year-old girls is a normal phenomenon, because precocious puberty refers to the clinical phenomenon of the development of sexual characteristics in girls before the age of eight and in boys before the age of nine. So, eight-year-old breast development is not considered precocious, and precocious puberty can be divided into true precocious puberty and partial precocious puberty, most of the partial precocious puberty is common, that is, the child does not have true sex hormone secretion increase as well as the bone age advancement and so on, most of the simple presence of breast development, can be due to the one-off intake of exogenous sex hormones caused. Therefore, it is necessary to pay attention to the baby to reduce or prohibit the intake of honey, health products, etc., may contain estrogen food, medicine, observation for a period of time, if soon appear sex signs development, to take the baby to the hospital in a timely manner for the age of the bone tablets, sex hormone series and other related examination, to determine whether it belongs to the true precocious puberty.