1.Clinical symptoms Acute hyperthermia, progressive anemia or significant bleeding, peripheral pain and weakness. 2.Signs Bleeding spots on the skin, sternal tenderness, lymph nodes, hepatosplenomegaly. 3.Laboratory (1) Blood picture White blood cells are always significantly increased (or decreased), may appear primitive or infantile cells. (2) bone marrow image Bone marrow nucleated erythrocytes accounted for less than 50% of all nucleated cells, primitive cells ≥ 20%, can be diagnosed as acute leukemia; such as bone marrow nucleated erythrocytes ≥ 50%, primitive cells accounted for ≥ 20% of non-red lineage cells, can be diagnosed as acute red leukemia.