Decitabine has been reported to have a clinically significant, often long lasting effect on the platelet count in myelodysplastic syndromes(MDS). It is also reported that decitabine could increase platelet counts by enhancing megakaryocyte maturation and platelet release. Immune thrombocytopenia(ITP) is known as an immune-mediated acquired disease characterized by transient or persistent decrease of the platelet count. However, refractory ITP is lacking of effective treatments and the efficacy of decitabine in ITP remains poorly understood. Data from this study may provide some idea of decitabine in the treatment of ITP.