Breast development is not very consistent from one woman to another. In general, breast development stops around the age of 16, and previous data suggest that the age of female breast development is around 11-15 years old. Women begin to develop from the initial primordial period of breast development, then to the gradual formation of interstitial hyperplasia of the alveoli and lobules of the milk ducts, and then to the development of subcutaneous tissue. Different women develop earlier or later, and the time period of development is not exactly the same. Over the years, with the change of lifestyle and the adjustment of diet structure, Chinese women generally have an earlier developmental time, while the time of cessation of development is relatively less.