Acute leukemia after chemotherapy platelets 770 × 10⁹ / L is not normal, this situation suggests the existence of elevated problems, considerations may be related to the application of hormones or blood concentration and so on, but also not except the bone marrow during the recovery period of hematopoietic function is active due to. 1. The use of hormonal drugs in the course of treatment: in the course of chemotherapy, if the use of glucocorticoid drugs such as dexamethasone, it may be induced to lead to an increase in platelet counts, which can be restored to normal after discontinuing the drugs. 2. The phenomenon of blood concentration: in the process of chemotherapy for the treatment of malignant tumors, the most common adverse reactions of patients are gastrointestinal adverse reactions, loss of appetite, nausea and vomiting, etc., at this time, there is a blood concentration or dehydration, resulting in platelet counts reactive elevation. 3. Hematopoietic activity during bone marrow recovery: chemotherapeutic drugs such as cytarabine will inhibit bone marrow proliferation in the short term, when the disease is in remission and bone marrow hematopoiesis is rebuilt, abnormal hematopoietic activity may occur, which is a normal manifestation, and will return to normal after a period of time. Clinical use of chemotherapeutic drugs lead to increased platelet count, it is recommended that patients consult the Department of Hematology of regular hospitals to find out the causes and receive standardized treatment by physicians.