When a girl’s breasts begin to develop at eight weeks and ten months, it may or may not be precocious puberty and needs to be combined with other symptoms and tests. Precocious puberty in girls is defined as the appearance of secondary sexual characteristics before the age of eight. If a girl’s breasts begin to develop at eight weeks and ten months, and the observation time is accurate and not earlier, and the child does not show any other development of secondary sexual characteristics and is not accompanied by any other symptoms, it is considered possible that the sexual development is normal. However, if the girl is eight years and ten months old and her breasts start to develop, you need to be alert to the possibility of precocious puberty, you can go to the endocrinology department of the hospital in a timely manner to improve the age of the bone, including bone age film, sex hormones, breast ultrasound and ovary ultrasound for the initial screening, and if necessary, you can do GNRH stimulation test, etc., in order to diagnose whether the sexual precocious puberty.