We studied diagnostic value of the index Blast of blood to the early diagnosis of leukemia by ADIVIA 2120i automated hematology analyzers. Aim: Compares the detection cell Blast of ADIVIA 2120i analyzers and classical method. Objectives: 200 blood samples from the Hematology Department of Cho Ray Hospital including blood cancer: acute leukemia, chronic leukemia, multiple myeloma, lymphoma and benign disease as: thallasemia, hemophilia... Method: Perspective study.