The cause of leukemia is not clear, and is currently thought to be related to physical, chemical, biological and genetic factors. 1. Physical factors: including ionizing radiation, chemical poisons and so on. Research shows that large amounts and large areas of radiation (such as X-rays and γ-rays) can inhibit the hematopoietic function of the bone marrow and reduce the immune function, thus inducing leukemia. 2. Chemical factors: exposure to and use of benzene and benzene-containing organic solvents, ethylenediamine, antitumor drugs such as alkylating agents, topoisomerase II inhibitors and other drugs are related to the occurrence of leukemia. 3. Biological factors: mainly abnormal immune function, viral infection, etc., such as human immunity defective patients, the risk of leukemia will be increased after the organism is infected with viruses, such as T-cell leukemia or lymphoma can be induced by human T-lymphotropic virus type Ⅰ. 4. Genetic factors: the genetic probability of leukemia is 0.7%. There are many causes of leukemia, and there may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then receive targeted treatment under the guidance of the physician.