Abstract: Objective: To investigate the misdiagnosed 6 of 52 patients with idiopathic thrombocytopenic purpura（ITP）, we will be better understand the myelodysplastic syndromes. Methods: According to the clinical and laboratory data of 52 patients with ITP, evaluated the misdiagnosed 6 cases. Results: 6 of 52 patients with ITP in the course of follow-up presented with anemia and neutropenia or monocytosis. 2 of 6 patients translated leukemia. 3 of 6 cases had abnormal karyotype. Conclusion: Pure thrombocytopenia can be the first symtom of myelodysplastic syndromes and that may mimic ITP, the classification of these cases is difficult, from a practical point of view such a diagnosis may be avoid inefficient and possibly harmful treatments.