Objective To explore the correlation between the cardiovascular ultrasound results and pathological findings of heterotaxia syndrome, analyze the cause of the difference, and improve the prenatal cardiovascular diagnostic accuracy of heterotaxia syndrome by ultrasound. Methods According to fetal autopsy or vessel casting, the ultrasound results of 37 fetuses with heterotaxia syndrome were retrospectively analyzed. The cardiovascular misinterpretations of ultrasound were summarized in the venous-atrial segment, atrial-ventricular segment and ventricular-arterial segment. Results ①Thirty fetuses underwent autopsy and seven fetuses vessel casting were included, there were 10 fetuses with left atrial isomerism and 27 fetuses with right atrial isomerism.Only one left isomerism was misdiagnosed and the diagnostic accuracy of atrial isomerism by ultrasound was 97.3%. ②Thirty-seven fetuses with heterotaxia syndrome included 206 cardiovascular malformations. Twenty-seven misinterpretations of ultrasound were found and the rate of cardiovascular misinterpretations was 13.1%. ③The cardiovascular misinterpretations of left atrial isomerism involved 1 secondary atrial septal defect in the atrial-ventricular segment and 1 aortic atresia, 2 anomalous position of arterial duct in the ventricular-arterial segment. ④The cardiovascular misinterpretations of right atrial isomerism in the venous-atrial segment included 4 common pulmonary vein atresia, 3 anomalous hepatic venous connection, 3 total abnormal pulmonary venous drainage, 2 persistent left superior vena cava and 2 abnormal inferior cava venous drainage. The cardiovascular misinterpretations of right atrial isomerism in the atrial-ventricular segment contained 2 secondary atrial septal defect, 1 unroofed coronary sinus and 1 partial atrioventricular septal defect. The cardiovascular misinterpretations of right atrial isomerism in the ventricular-arterial segment involved 3 double-outlet right ventricle, 1 truncus arteriosus and 1 anomalous position of arterial duct. Conclusions The correspondence between ultrasound results and pathological findings about cardiovascular malformations of heterotaxia syndrome is high. The most common cardiovascular misinterpretations of left atrial isomerism involve the ventricular-arterial segment. And the most common cardiovascular misinterpretations of right atrial isomerism involve the venous-atrial segment. Key words: Ultrasonography, prenatal; Heart defects, conginatal; Heterotaxia syndrome