Abstract: Polycystic ovary syndrome（PCOS） is the most common endocrine disorder in women. This syndrome often occurs in perimenarcheal girls. Some of the pathological features of adolescent PCOS are often similar to the physiological changes of puberty. How to make the diagnosis of adolescent PCOS is difficult for clinician.

Key words: Puberty, Polycystic ovary syndrome, Menstruation, Hyperandrogenism, Metabolic diseases, Diagnosis