The etiology of leukemia is still unclear, and there is a close correlation with the following factors, as follows: 1, viral infections: certain specific viral infections, which can lead to the occurrence of adult T-cell leukemia; 2, radioactive substances: such as radioactive sources cobalt-60; 3, chemical substances: such as the shoe industry, electronic products, containing benzene or benzene derivatives, formaldehyde, etc., long-term exposure susceptible to disease; 4, chemotherapy drugs: such as cyclophosphamide, alkylating agents, VP-16, VM-26 and other chemotherapy drugs, susceptible to leukemia.