The first menstruation of a girl is called menarche and marks the beginning of puberty. The age of menarche in China is between 10 and 16 years old, with the average being around 12-13 years old. Therefore, it is common for 10-year-old girls to have their first menstruation slightly earlier. This phenomenon is related to many factors, and it is necessary to go to the hospital to check sex hormones to exclude whether it is precocious puberty. Factors affecting the early age of menarche are related to the following: 1. Genetic and congenital factors: the age of the mother’s menarche is related to the age of the daughter’s menarche, i.e. the earlier the mother’s age of menarche, the greater the possibility of the daughter’s early age of menarche. 2. 2, environmental factors: girls in northern China have an earlier age of menarche; family tension, sudden changes in family economic status, family changes, violence, academic pressure, etc., can lead to an earlier age of menarche. 3, nutritional factors: good nutritional status, less time for outdoor activities and physical exercise, causing overweight, obesity, which in turn leads to an earlier age of menarche. 4, lifestyle, behavior: frequent consumption of animal food, nutritional supplements, sugary drinks, as well as premature exposure to romantic dramas, yellow information, etc. can lead to early development of girls. After the first menstruation, girls will become sexually conscious, show significant emotional and intellectual changes, and get excited easily. If exposed to the above factors for a long time, it is easy to induce a series of social problems in children, such as early sexual life, unwanted pregnancy, early marriage and premature birth. Therefore, after a 10-year-old girl gets her period, her family should teach her child the correct knowledge of girls’ physiological hygiene as well as child sex education, pay close attention to and care about the child’s psychological, emotional and social behaviors, and intervene and care for inappropriate behaviors when found. If the family finds that the child’s menstrual cycle is not very regular within the first few years after her first period, there is no need to worry too much; after 5-7 years, the menstrual cycle will gradually become regular.