Physiological changes during puberty include the development of the whole body, the development of the first sexual sign, the appearance of the second sexual sign and the onset of menstruation. 1. Total body development: due to the influence of estrogen and growth hormone in the body, the height of a girl will grow rapidly and her body shape will change. 2. Development of primary sexual characteristics: the external genitalia of girls will grow and develop during puberty, specifically manifested in the bulging of the pubic mound, thickening of the labia, enlarging of the uterus, thickening of the fallopian tubes, and enlarging of the ovaries. 3. Appearance of secondary sexual characteristics: female sex hormone secretion increases during puberty, which will stimulate breast development to a certain extent, which is a characteristic of the early appearance of secondary sexual characteristics, and is also a typical sign of entering puberty. 4. Menstruation: When the secretion of estrogen reaches a certain level during puberty, the endometrium will shed periodically, thus menstruation occurs. Physiological changes in girls’ puberty are also manifested in other aspects. At this stage, good nutritional supply and psychological education should be ensured to ensure their safe and healthy growth.