Primary immunodeficiency disease is a genetic disorder. Since the first case of primary immunodeficiency disease was discovered by Bruton in 1952, more than 150 types of primary immunodeficiency diseases have been identified to date, and the number of new primary immunodeficiency diseases is growing at a rate of one to two per year. Regarding the incidence of primary immunodeficiency diseases, many countries around the world have launched nationwide primary immunodeficiency disease registries and published their incidence. Since a comprehensive primary immunodeficiency disease registry has not yet been established in China, there is a lack of statistical data in this regard. According to foreign data, its incidence was considered to be about 1/10,000 in the 1980s, but with the development of science and technology and the increased awareness of the disease, its incidence is now considered to be 1/5,000, which is a high incidence disease among genetic disorders. Primary immunodeficiency diseases usually develop in infancy and childhood, but some types of primary immunodeficiency diseases can develop at a later age or even in adulthood, with approximately 40% of cases developing within 1 year of age, 40% within 5 years of age, 15% within 16 years of age, and only 5% in adulthood. According to the 1997 WHO classification criteria for primary immunodeficiency diseases, primary immunodeficiency diseases are classified as combined immunodeficiency, humoral immunodeficiency with antibody deficiency, cellular immunodeficiency with T-lymphocyte deficiency, immunodeficiency with other important features, defective phagocyte number and function, complement deficiency and immunodeficiency accompanied or secondary to other congenital or genetic diseases. There are seven major categories. From the current clinical reports, all the above-mentioned categories of diseases are involved in China, and as the clinical understanding of primary immunodeficiency diseases and the level of diagnostic techniques continue to improve, more and more cases are found, which is closely related to the rapid development of immunomolecular biotechnology. The diagnosis of primary immunodeficiency diseases at the genetic level is now possible in China. Primary immunodeficiency diseases are highly heterogeneous, with clinical manifestations ranging from increased susceptibility of the organism to microorganisms, to metaplasia and autoimmunity, as well as lymphoid tissue hyperplasia and tumors. In terms of treatment, intravenous immunoglobulins have been widely used in primary immunodeficiency diseases for the past 20 years or so, but are expensive and not curative. In contrast, HLA-matched HSCT and gene therapy are the only effective ways to cure most primary immunodeficiencies. Hematopoietic stem cell transplantation for primary immunodeficiency diseases has been widely performed in developed countries, and much work has been done in this area in Hong Kong, China, but so far it has not been reported within the mainland. In primary immunodeficiency diseases, hematopoietic stem cell transplantation is mainly used in two areas: lymphatic lineage immunodeficiency, such as hyper IgMemia, severe combined immunodeficiency and eczema thrombocytopenia with immunodeficiency syndrome; and myeloid lineage immunodeficiency, such as chronic sarcoidosis and leukocyte adhesion deficiency. Because hematopoietic stem cell transplantation can save the lives of patients with primary immunodeficiency diseases, it should be performed immediately upon diagnosis; otherwise, if the patient develops irreversible infections and complications, the transplantation will be difficult to succeed and the significance of the transplantation will be lost. Therefore, in many countries, hematopoietic stem cell transplantation in patients with primary immunodeficiency diseases is treated as an “emergency”. In conclusion, there are still many problems in China regarding primary immunodeficiency diseases. For example, screening and registration are not yet sound nationwide or locally; molecular biology diagnosis is obviously lagging behind; some children are unable to adhere to standardized treatment due to the high cost of treatment; and there are no cases of bone marrow transplantation yet due to the lack of timely detection of cases, lack of sufficient donor sources and insufficient attention from society. With the significant increase of cases of primary immunodeficiency diseases found in China, it is important to draw the attention of the society and medical community. Currently, developed countries abroad have established corresponding associations or organizations for primary immunodeficiency diseases, calling on the whole society to care for these patients.