Objective To investigate the correlation between the morphological features of erythroblastic islands (EI) and clinical outcome. Methods The incidence and maturity of EI were measured by morphological examination.Results The incidence of EI was highest in acute erythremia, acute erythroleukemia, and iron deficiency anemia (75.0%?70.0%?63.6%, respectively), while very rare in aplastic anemia, acute leukemia (acute erythroleukemia excepted ), lymphoma. In addition, EI incidence in leukemia was significantly higher after remission than at presentation (43.7% vs 0, P