Objective To investigate the electrocardiogram characteristics and mechanism of spontaneous premature contractions that reveal dual atrioveentricular nodal pathways（DAVNP）. Methods The data of 8 typical cases were analyzed and discussed. Results The DAVNP were suggested when ECG showed the following manifestations:（1）RP interval was similar or equal between early atrioventricular and early atrioventricular

while PR interval was quite different;（2）early atrial or ventricular premature induced（or stopped） prolonged or shortened leap of PR interval and involved multiple beats（repeat between two paths）;（3）Atypical Wenckbach phenomenon appeared in short atrial tachycardia

and PR interval was different in the same or similar RP;（4） Ventricular premature or atrial premature induces 1:2 atrioventricular conduction;（5）The "contradictory" phenomenon in atrioventricular conduction:a. The PR interval associated with spontaneous premature beats is contrary to the expectation based on the "RP/PR relationship"; b. Sinusoventricular fusion wave appeared in the short PR’ interval

but did not appear in the long PR’interval;（6） The frequency of AVRT induced by atrial early onset was related to the short and long P’R interval.Conclusions Spontaneous premature beats have the same effect as electrophysiological examination in revealing DAVNP which is non-invasive

safe and practical.Should cause enough attention of clinic and electrocardiologist.