Primary immune thrombocytopenia ( ITP) is an organ-specific autoimmune hemorrhagic disease. The etiology of ITP is still unclear, but loss of immune tolerance to platelet surface antigens is con-sidered as a fundamental cause of ITP. Therapeutic strategies that prevent the activation and proliferation of autoreactive cells have been suggested, which includes clearance of autoreactive cells ( apoptosis) , receptor editing, induction of anergy and extrinsic cellular suppression. Failure at any of these steps may lead to the production of autoantibodies against platelet and megakaryocyte glycoproteins. An improved understanding of the mechanisms for autoantibody production will provide theoretical basis for optimal diagnosis and treatment of ITP.