Children with recurrent fever to exclude leukemia, can be from clinical symptoms, blood routine, coagulation function, bone marrow smear, immunohistochemistry several integrated to determine. 1. Clinical symptoms: leukemia patients are usually accompanied by fever, bleeding gums or nasal cavity, anemia and other manifestations of the three systems of reduction. It can also be accompanied by chest pain and other symptoms. 2. Blood routine and coagulation function: blood routine shows that one or several items of white blood cells, red blood cells and platelets are less than normal, and may be accompanied by coagulation dysfunction. 3. Bone marrow smear: Bone marrow smear shows that leukemia cells are of different sizes, with rough nuclear chromatin, uneven distribution and larger nuclei than normal primitive cells. Most of the bone marrow images show active proliferation, obvious activity or extreme activity, while normal hematopoietic cells are obviously inhibited. 4. Immunohistochemistry: Immunohistochemistry for leukemia typing, help to clarify the diagnosis. If your baby has recurrent fever, it is recommended to consult a doctor in time, complete the blood tests under the guidance of the doctor, make a clear diagnosis, and then follow the doctor’s instructions to provide targeted treatment.