Breast development generally begins between the ages of nine and twelve for girls. Breast development in girls usually occurs after puberty, but the timing of breast development varies depending on individual circumstances such as dietary or lifestyle habits. Normal girls enter puberty between the ages of nine and twelve when their breasts begin to develop. The exact time of development varies from person to person. Girls in the stage of breast development should improve the way of eating or living habits, eat more fruits and vegetables and meat, eggs, milk and beans and other foods, should ensure that the daily nutritional balance, to ensure that the development of normal and healthy. If a girl’s breast development is too early or too late, as well as breast development in the process of adverse conditions, it is recommended to go to the endocrinology department of a regular hospital in a timely manner, in accordance with the doctor’s instructions for targeted treatment.