Unlike infectious diseases, leukemia does not have an exact incubation period, but there is a difference in the duration of the disease. Leukemia is divided into acute leukemia and chronic leukemia, which is a clonal disease with mutations in acquired hematopoietic progenitor cells. Acute leukemia is mainly due to chemical drugs, ionizing radiation, genetics, viruses and other causes, the onset of the disease is acute, the course of the survival period is also relatively short. Chronic leukemia, on the other hand, is more insidious, with a slower disease course and a longer survival period, even up to 10-20 years in some patients. Whether it is acute leukemia or chronic leukemia, the duration of the disease is also related to the type of leukemia, the onset of the disease, environmental factors, physical fitness, treatment effects, complications and psychological conditions and other factors. Therefore, there is no definite incubation period for leukemia. Leukemia patients should go to the hospital to receive regular examination and treatment, and regularly monitor the dynamic changes of the blood picture, so as not to miss the best time for treatment.