The high incidence of leukemia is as follows: 1. 2-9 years old: this period is the high incidence of acute lymphoblastic leukemia in children, when the immune function of children is not fully developed, stimulated by the environment and the influence of their own genetic background, which can easily cause the occurrence of acute lymphoblastic leukemia; 2. old age: especially older people over 65 years old, with the growth of age, human DNA is subject to external factors more influenced and prone to mutation; if the DNA of hematopoietic stem cells is mutated, it will cause the occurrence of acute leukemia. In addition, leukemia can also occur in young adults between the ages of 30-40, but 30-40 is not the high incidence age.