When acute leukemia is suspected, hospitalization is performed and the diagnosis is made again. A peripheral blood test is performed, which may show an increase or decrease in white blood cells, and may show anemia, thrombocytopenia, and a decrease in whole blood cells; peripheral blood sorting can sometimes detect naïve cells; and primitive naïve cells greater than 20% can be detected by bone marrow aspiration smear. Immunophenotyping is also observed, and primitive naïve cells greater than 20% can usually be detected by bone marrow flow cytology. Chromosomal examination as well as genetic examination can determine the prognosis and stratify the treatment. For acute leukemia, the diagnosis is mainly based on the patient’s clinical symptoms, such as anemia, bleeding, infection, or bone pain, combined with laboratory tests, including peripheral blood, bone marrow, chromosomal, immunophenotyping, and genetic tests.