Altered myelogram is a phenomenon that refers to changes in the degree of bone marrow cell proliferation, bone marrow cell count, granulocyte-red ratio, and the ratio of hematopoietic cells in each system and stage. The following is an example of how to effectively prevent myeloid changes in leukemia. 1, all work exposure to ionizing radiation and toxic chemicals benzene and its derivatives of the staff, should strengthen protective measures, carefully according to the work routine operation, regular physical examination, a amount of blood abnormalities should be actively treated. 2, life in moderation, beggars live in a regular manner, to avoid the cold and heat, the combination of work and rest, so that the body in good condition, the so-called: “the righteousness of the bones, the evil can not dry”. 3, people should be optimistic, relaxed mood, avoid depression and anger, the so-called: “spirit within the guard, the disease is safe from”. Life should be regular, careful to avoid cold and heat, combining work and rest, regulate the mood, avoid depression and anger, keep the mood relaxed, so that the body in a good state. “The righteousness exists within, the evil cannot dry”. In addition, staff who are exposed to ionizing radiation and toxic chemical substances (benzene and its derivatives) at work should strengthen protective measures and have regular physical examinations. Drugs that are damaging to bone marrow cells, such as chloramphenicol and bivalirudin, are prohibited.