Electrocardiosignal (ECG) is an important evidence base for the diagnoses of cardiovascular diseases as well as for the researches in basic and clinical medicine. Because it presents typical non-steady signals, the wave in time can not reflect the essential characteristic very well. In this article, by analysis in time-frequency domain, we have obtained some typical time-frequency diagrams of normal ECG and abnormal ECG, which reflect the comparatively essential characteristics of the original signal in some aspects and seem likely to become a basis for validating the relevant diagnosis.