Generally speaking, when a girl enters puberty, i.e., at the age of 9 to 11, her breasts will start to develop, and she should pay attention to good habits, reasonable diet and exercise at this time. When a woman enters puberty, her breasts begin to develop, starting with the nipple protruding, then the breasts gradually become larger, the areola gradually deepens, and may be accompanied by a feeling of swelling and pain. Due to different nutritional status, heredity and so on, there are great individual differences in development. However, there is development until the age of 16. If the breasts have not developed by the age of 16 or have developed before the age of 8, you should go to the doctor. After entering puberty, parents should educate their children so that they can face up to the changes in their bodies. At the same time, they should provide nutritional protection for their children’s diets, with normal intake of vitamins and proteins. They should exercise properly, have a regular routine, and not stay up late at night. In addition, parents should give the child to choose the right corset, to be comfortable not to restrict the development of breasts.