Abstract: ObjectiveTo report 6 cases of megaloblastic anemia (MA) characterized by granulocytic series with extreme or significant hypercellularity and giants. MethodThe characteristics of usual clinic, hemogram and myelogram of MA characterized by extreme or significant hypercellualrity and giants were analyzed with morphologic examination. ResultsIn these cases, there were mostly significantly decreased WBC and Plt in peripheral blood and granulocytic series with extreme or significant hypercellualrity and giants but erythrocytic series with not significant hypercellularity and decreased cell quantity indeed in bone marrow. There was erythrocytic series mostly with slightly or intermediately megaloblastic changes. There were rubriblasts and prorubricytes with less or no typical megaloblastic changes which could be seen in general MA. There was significant therapy effect with vitamin B12 or vitamen B12 and folic acid as general MA. ConclusionThe MA characterized by granulocytic series with extreme or significant hypercellularity and giants was a special type of MA. It is easy to diagnose incorrectly and difficult to diagnose due to deficient cognition to it.