Acquired immunodeficiency disease, also known as AIDS (HIV), is familiar to everyone, but primary immunodeficiency disease, for most people, can only be a legend in the jungle. Most primary immunodeficiency diseases occur in infants and children, and one type can occur in adults, which is what we will call CVID, or common variant immunodeficiency disease. CVID is a rare form of hypogammaglobulinemia, a group of primary immunodeficiency diseases with different etiologies that mainly affect antibody synthesis. The clinical manifestations are diverse and can affect both men and women, with onset in early childhood, but more often in school age or even in adulthood. The main manifestations are: 1) refractory infections; 2) gastrointestinal symptoms: chronic malabsorption syndrome, steatorrhea, lactose intolerance, disaccharidase deficiency, protein-losing enteropathy, etc. 3. A few patients may present with lymph node and splenomegaly. The incidence of this disease is very low, very few Asians, it is said that 1-2 people per 2 million people, can be manifested as familial, can also be disseminated, non-infectious. Treatment is mainly to prevent infection and regular infusion of immunoglobulin.