How long chronic granulocytic leukemia needs to be treated varies from person to person and cannot be generalized. Below is a description of how long it takes to treat a patient with chronic granulocytic leukemia, separated from the first-generation targeted drugs and the second- and third-generation targeted drugs. 1. Taking patients treated with TKI-targeted drugs as an example, usually it is required to take oral first-generation TKI drugs such as imatinib for more than 2 years, and the fusion gene test is negative for more than 2 years, then it can be considered to temporarily stop taking the drug, but some patients will have a relapse within one year, and need to restart taking the drug treatment. Some patients need to receive drug treatment for life. 2. Patients who have been treated with second- or third-generation TKI drugs for more than two years and have maintained a negative fusion gene test for more than one year may also be able to suspend taking the drugs. Drugs include dasatinib, ponatinib and so on. Patients with slow-grain leukemia need to regularly review blood tests and genetic tests, etc. Slow-grain patients should consult their doctors before ending treatment, and should not stop taking medication blindly. Drug use is under the guidance of a physician.