Objective To evaluate the value of dual Doppler ultrasonography in the diagnosis of fetal atrial extrasystoles.Methods Seven thousands and thirteen fetuses were examined by fetal echocardiography.If fetal arrhythmias were found,information of pulsed wave Doppler signals in hepatic vein (HV) and descending aorta (DAo) using dual Doppler were colleted simultaneously.The detected times were compared between using general Doppler and dual Doppler in 20 cases.Results On dual Doppler examination,28 of the fetuses showed signals of atrial extrasystoles,14 fetuses atrial extrasystoles conducted to ventricle,8 fetuses atrial extrasystoles non-conducted to ventricle,6 fetuses with part of the extrasystoles conducted to ventricle and part of the extrasystoles non-conducted to ventricle.No case had congenital heart disease.Twenty-six fetuses with atrial extrasystole were converted to normal rhythm within the third trimester of pregnancy,and the others' were converted to normal rhythm during the first 3 days postnatally.The detected time of dual Doppler was shorter than that of general Doppler(P ＜0.05).Conclusions Dual Doppler ultrasonography of simultaneous recordings in HV and DAo is an easy,rapid method of assessing fetal atrial extrasystoles,which should allow precise diagnosis of atrial extrasystole.