Menstruation at the age of 10 and a half is generally considered normal. Menstruation refers to the cyclical shedding of the endometrial lining of the uterus and bleeding under endocrine regulation. The age of menarche can be as early as 11 years old and as late as 18 years old. However, some menstruation occurs a little earlier or later, around 10 and a half years of age, which is considered normal and does not require special treatment. During puberty, the ovaries begin to develop and secrete estrogen, which acts on the endometrium, which undergoes cyclic changes. When the secretion of estrogen and progesterone decreases, it causes the endometrial tissues to become necrotic and shed, and blood vessels to rupture and bleed, which is why menstruation occurs. When girls first start menstruating, due to the development of the hypothalamic-pituitary-ovarian axis is not particularly mature, the menstrual cycle is not particularly regular, this is a normal physiological phenomenon, with the gradual development of the ovarian axis mature, will establish a normal menstrual cycle. Girls should pay attention to menstrual hygiene during menstruation. The key to good menstrual hygiene and health care is to teach girls about menstrual physiology and hygiene in a timely manner, and to prepare their minds to avoid anxiety or depression. Other developments such as height, weight and secondary sexual characteristics should be monitored at all times.