Aplastic anemia is a disease characterized by low bone marrow hematopoietic function and derease of whole blood cells caused by a variety of reasons. Its pathogenesis includes abnormality of hematopoietic stem cells (seed theory), hematopoietic microenvironment (soil theory) and immune function (such as worms theory). These 3 causes of disease interact each other and facilitate the development of aplastic anemia, thereby increase the complexity of the etiological diagnosis and uncertainty of treatment. On this basis, this review summarizes the latest research progress on the blood supply of bone marrow microcirculation in the hematopoietic microenvironment, stromal cells, cytokins, the immune function of dendritic cells, natural killer cells, T cell subgroup, the secretion of cytokines, cell signal transduction, and hematopoietic stem cell gene abnormality to provides the theoretic basis for the diagnosis and treatment of aplastic anemia.