Acute pulmonary embolism (APE) has high morbidity and mortality. So, it is very important for the APE patients to get an appropriate diagnosis and risk stratification as early as possible. Electrocardiogram (ECG) could finely reflect a series of pathological and physiological process caused by APE pulmonary hypertension, and has a good relation with the pulmonary perfusion defect, right ventricular dysfunction and severe in-hospital complications. In this paper, we review the correlation of various ECG waveforms and Daniel ECG score with the severity of pulmonary embolism. We aim to evaluate the roles of ECG in risk stratification of the pulmonary embolism.