Generally speaking, most girls show breast development at the age of 9~11 years old, and the appearance of breast development in girls at the age of 8 weeks may be abnormal, alert to the possibility of precocious puberty. When breast development occurs, the first thing that can be seen in the appearance is the protrusion of the breasts, the areola will be formed slowly, and the nucleus of the breast will be felt when touched with the hand, and the child will also feel the swelling and pain of the breasts. Generally speaking, most girls show breast development at the age of 9 to 11, but nowadays, with the improvement of living standard, many foods contain hormones, so the child’s puberty development period may appear earlier. In addition, parents should also observe the development of secondary sexual characteristics, if the child also appears pubic hair growth, menstruation, that the child is a normal stage of pubertal development, do not worry too much. When 8-year-old girls have breast development, parents should pay attention to whether the child’s breast nucleus has a particularly enlarged phenomenon, or appear red and swollen, in this case, you can go to the endocrinology department of the hospital, check the child’s endocrine hormones have no abnormal situation.