The age of first menstruation in women tends to be between 13 and 14 years of age, but can be as early as 11 or as late as 16. The onset of regular menstruation is an important sign of maturation of reproductive function. The first menstrual period is called menarche. The age of first menstruation in women tends to be between 13-14 years of age, but can be as early as 11 years or as late as 16 years. The age of menarche is mainly influenced by genetic and nutritional factors. Mothers and daughters have a similar age of menarche, and well-nourished, slightly chubby girls have an earlier menarche. However, if the onset of menstruation occurs earlier than 11 years of age, precocious puberty should be considered. The absence of secondary sexual characteristics at age 14 or the development of secondary sexual characteristics at age 16 are considered primary amenorrhea, which is mostly caused by genetic reasons or congenital developmental defects. Therefore, parents need to pay attention to their children’s growth and development. If the age of menarche appears at the wrong age, they should go to the hospital in time for early intervention and treatment to minimize the impact on growth and development.