Abstract: 【】 Objective To investigate electrocardiogram(ECG) finding about leukemia with different types after chemotherapy,so as to provide scientific evidences for prevention and treatment of cardiotoxicity associated with chemotherapeutics in the future. Methods ECG results concering acute leukemia during different phase of chemotherapy in 209 patients were summarized and analyzed,to analyze ECG results related to chronic leukima in 30 patients before and after chemotherapy.Results ST-T change,sinus tachycardia,left ventricular high voltage,premature and conduction block are more common abnormal ECG change in patient with leukemia after chemotherapy.Consolidation phase present the highest rate of abnormal ECG, and the rate shows statistical significance in comparasion with other two phases in acute leukemia(P<0.05).Nevertheless the difference between the acute lymphoblastic leukemia(ALL) and the acute myelogenous leukemia(AML) is in distinctive(P>0.05), and it is the same in their each type(P>0.05).The abnormal ECG rate of patients with chronic leukemia will improve after chemotherapy. Conclusions Chemotherapeutics can lead to severe cardiotoxicity so that frequent monitoring of ECG change should be instituted during chemotherapy treatment in patient with leukemia,in order to discover myocardical damage as well as measures of myocardical protection should be taken before it is too late.