Abstract: Insufficiency of ECG diagnostic skills of clinicians is in some way related to the neglect of ECG vector theory in traditional ECG teaching. To achieve the teaching goal of improving ECG diagnosis ability of clinicians, heuristic ECG teaching based on ECG vector theory is proposed and its implementation strategy is discussed. During the teaching process, ECG interpretation test and questionnaire survey were used to evaluate the teaching effects objectively. The results showed that the scores in heuristic teaching group were higher than those in traditional teaching group. At the same time, problems of heuristic ECG teaching during the implementation were also analyzed to optimize this teaching mode.