Different types of leukemia have different ages of susceptibility, for example, acute lymphoblastic leukemia is usually found in children aged 0~9 years old. 1. Acute lymphoblastic leukemia: generally common in children, with peak incidence at 0~9 years old. 2. Acute myeloid leukemia: it can occur at all ages and is more common in adults. The incidence rate increases with age, and the median age of onset is close to 70 years old. 3. Chronic granulocytic leukemia: it can occur in all age groups, with a median age of onset at 45-50 years. 4. Chronic Lymphocytic Leukemia: Chronic lymphocytic leukemia is most common in the elderly. There are other types of leukemia, in general, leukemia can occur in all ages, usually should pay attention to observe their own and their family’s physical condition, once the discomfort or abnormal performance, should go to the hospital in time.