Myelosuppression often appears 7-14 days after targeted drug therapy, and myelosuppression never recovers after targeted drug therapy for leukemia, which is considered to be related to the high dose of chemotherapeutic drugs, infection, and leukemia relapse. Common targeted drugs include Vinaclat, Sorafenib, and so on. 1. Over-dose of chemotherapy drugs: During chemotherapy of targeted drugs, the dose of drugs needs to be adjusted according to the results of patients’ blood routine in order to initially determine the appropriate dose of chemotherapy drugs. If the dose of chemotherapeutic drugs is not reasonable, it will lead to slow recovery of myelosuppression. 2. Infection: If bacterial, fungal or viral infection occurs during treatment with targeted drugs, it will further inhibit the hematopoietic function of bone marrow and lead to slow recovery of myelosuppression. 3. Leukemia relapse: if there is leukemia relapse, the recovery of bone marrow suppression after targeted drug therapy will also be slower. If the bone marrow suppression does not recover after targeted drug therapy for leukemia, there may be other reasons, such as differences in individual drug tolerance, the condition has not reached remission, etc. It is recommended to go to the hospital in time to improve the examination under the guidance of the physician to clarify the cause of the disease. The use of targeted drugs should be carried out under the guidance of a physician.