The cellular composition of remission marrow from patients with acute myelocytic leukemia (AML) was studied in order to obtain informations for the prediction of relapse. Hematological findings such as (1) Myeloblast 3%, (2) Promyelocyte 12%, (3) Erythroblasts 45% and (4) Erythroblasts 15% were thought to be atypical in remission marrow. Among these atypical finings, the coexsistence of (1) and (3) or (1) and (4) were important in the prediction of relapse. In the first month after the recognition of (1)+(3) or (1)+(4), the cumulative relapse rate was 35% and 50%, respectively. The rates were 71% and 58% by the second month, respectively. The median remission duration of patients treated within two weeks after the recognition of (1) was longer than that of patients treated after two weeks (4.7 months vs 1.5 months, p<0.05). These results indicate that the coexsistence of atypical findings, (1)+(3) or (1)+(4), are important not only in the predicting of the relapse of AML but also to analyze the dyshemopoiesis of preleukemic states or myelodysplastic syndromes.