Idiopathic thrombocytopenic purpura(ITP) is a common bleeding disorder in childhood. Approximately 80% of the disease is acute self-limited, most has minimal bleeding and achieves spontaneous recovery of platelet count. Even for the remaining who becomes chronic defined by persistent thrombocytopenia more than 6 months from the onset, high rates of complete or partial remission are also predicted. Because of generally benign outcome in childhood ITP as well as limited efficacy of treatment which is of no more than temporary benefit, therapeutic intervention to newly diagnosed ITP or to chronic disease for the prophylaxis of major hemorrhage continues to be controversial.