Childhood uterus, also known as uterine hypoplasia, is characterized by a normal uterine structure and morphology, but with a small uterine body and a relatively long cervix. The most common types of infantile uterus are the adolescent uterus, which has a 1:1 ratio of uterine cavity to cervix, and the infantile uterus, which has a 1:2 ratio of uterine cavity to cervix, and the latter is often associated with ovarian hypoplasia. An infantile uterus is a uterine underdevelopment of varying degrees that occurs when the uterus stops developing during embryonic life, late gestation, or at any time after birth until puberty. A naïve uterus typically presents with a small uterine corpus, a relatively long cervix, and significant positional abnormalities such as excessive forward or backward flexion. Naïve uterus may show delayed onset of menstruation with scanty menstruation, dysmenorrhea and primary amenorrhea. If, after puberty, a girl has delayed menstruation or scanty menstruation, and the development of secondary sexual characteristics is not obvious, she should be alerted to the abnormal development of the reproductive system, and should consult a doctor in time for examination and treatment. Childish uterus should be examined and detected early, so for adolescent girls, it is best to have a physical examination to detect abnormalities early.