Ten-year-old girls with armpit and pubic hair development is usually considered to have begun puberty, whether it is normal also need to be combined with the time of breast development, such as breast development before the age of 8, followed by the appearance of armpit hair, etc. is considered abnormal, for precocious puberty. The development of axillary and pubic hair in 10-year-old girls is usually considered to be the emergence of secondary sexual characteristics, and the beginning of puberty, the age of the beginning depends on the time of the initiation of the function of the gonadal axis, which usually starts around 10 to 12 years old, and the development of puberty follows a certain pattern, such as breast development first, followed by the emergence of pubic hair, changes in the external genitalia, etc. The development of the breasts and pubic hair is the first step in the development of the pubertal development. Whether the above phenomenon is normal or not needs to be analyzed specifically. If the first breast development occurs before the age of 8, it is considered abnormal and there is precocious puberty, which refers to the emergence of secondary sexual characteristics before the age of 8, and it may affect the height in the future. If the first sexual development occurs after the age of 8, it is considered normal, but needs to be judged by a specialist. It is recommended to consult a specialist for a comprehensive assessment to determine if this is normal.