Girls begin to grow pubic hair after about 11 to 12 years of age. Girls enter puberty at about 10 to 12 years of age, and the general order of pubertal development is breasts, pubic hair, external genitalia, menstruation, and armpit hair. Breasts begin to develop first, which is also a sign of puberty, and then other secondary sexual characteristics such as pubic hair gradually begin to grow, and the whole process takes about 1.5 to 6 years. Therefore, pubic hair grows about 1~2 years after breast development, and the average age is after 11~12 years old. Due to the influence of pubertal hormone levels, genetic factors and other aspects, the time of pubic hair growth is not certain, and the judgment of pubertal development is also based on other secondary sexual characteristics. If there are abnormalities in growth and development, it is important to go to the hospital in time.