Ear circumference depression is one of the symptoms of pediatric Diegeorg’s syndrome. Diegeorg’s syndrome, or congenital absence or hypoplasia of the thymus, is a primary cellular immunodeficiency disease. It is a congenital anomaly caused by the absence or underdevelopment of the thymus and parathyroid glands due to impaired development of the third and fourth pharyngeal sacs during embryonic life. Affected children are often accompanied by other congenital malformations. So how can it be prevented? 1, strengthen care and nutrition to improve the patient’s resistance and immunity. 2.Prevent infection should pay attention to isolation to minimize the contact with pathogens. 3, avoid vaccination to suspected cellular immunodeficient newborns, often due to inoculation cowpox and systemic cowpox rash, inoculation lyophilized BCG vaccine and systemic spread of death. Therefore, live vaccines such as cowpox and lyophilized BCG should be prohibited, and measles and polio vaccines should be avoided.