It is generally seen that platelets will start to recover around 21 to 28 days after chemotherapy for leukemia. However, the situation will be different according to different disease progression. 1. 7~14 days of chemotherapy for leukemia is in the period of myelosuppression after induction therapy, and routine blood test within this period will show low platelets, which is normal; meanwhile, the bone marrow will be rechecked, so that the treatment plan can be adjusted according to the residual situation of primitive cells in the bone marrow. Chemotherapeutic drugs include cytarabine and Zoerythromycin. 2. After 21~28 days of chemotherapy for leukemia, the bone marrow suppression period has passed, and the bone marrow hematopoiesis is restored, and the bone marrow and blood images are rechecked. If the state of complete remission is reached, the platelet count can gradually return to normal; if the state of complete remission is not reached or is still in proliferative hypoplasia, and the platelet count is still in the state of hypoplasia, it means that the induction treatment plan of the regimen is not good, and the next step of treatment should be considered. If there is any relevant change, please consult your doctor in time and follow the doctor’s instructions for standardized treatment.