I. Parents need to provide a detailed and complete medical history Parents’ height, age of parental development, any special family history of disease. The child’s birth, diet, whether taking special medications (including health supplements, etc.), and the child’s height growth. Sexual characteristics development: girls include breast enlargement, whether there are hard lumps, areola color, vulva size and color, vaginal discharge, pubic hair, axillary hair, vaginal bleeding, etc.; boys include beard, throat knot, breast, testicles, penis, pubic hair, axillary hair, spermatorrhea, voice change, etc. In addition, whether the patient suffers from some special chronic diseases such as asthma, rhinitis, kidney disease, etc. Bone age is determined according to the hand and wrist x-ray to assess whether the bone is overdeveloped. In children with precocious puberty, the bone age is usually older than the actual age. The left palm and forearm should be flat and the fingers should be naturally separated when taking the film. Choose pelvic ultrasound to check the development of ovaries and uterus in girls; pay attention to testicles and adrenal cortex in boys. Girls should pay attention before the examination: hold urine. IV. Plasma sex hormone measurement No fasting is required when blood is drawn. The report will not be issued on the day of examination. V. CT or MRI examination Those who suspect intracranial tumor, ovarian tumor or adrenal gland disease should undergo cranial or abdominal CT or MRI examination. Note: The examination needs to be scheduled in advance, especially MRI. Other examinations can be selected according to the clinical manifestations of the child: T3, T4 and TSH can be measured if hypothyroidism is suspected; testosterone and estradiol concentration can be increased in gonadal tumors; blood 17-hydroxyprogesterone and urinary 17-ketosteroids are significantly increased in children with congenital adrenocortical hyperplasia. In children with congenital adrenal hyperplasia, blood 17-hydroxyprogesterone and urinary 17-hydroxyprogesterone are significantly increased. Note: Fasting is required on the day of the blood test, and no report will be issued on the day of the test.