From Jan. 2005 to Dec. 2006, we used 3-colour-fluorescence panel of Becton Dickinson Company (USA) and Flow Cytometry Facs Calibur machine to immunophenotype 220 patients with acute leukemia at Blood Transfusion and Hematology Hospital. Results: The results as follows: 117 patients with AML, 98 patients with ALL, và 5 patients with biphenotypic leukemia.