Abstract: Objective：To investigate the value of blood flow in fetal ductus arteriosus for predicting and evaluating prognosis of congenital right heart malformations after birth. Methods：Totally 68 fetuses prenatally diagnosed as congenital right heart malformations from February 2015 to February 2017 were divided into 3 groups based on the blood flow in fetal ductus arteriosus: group A with forward blood flow, group B with bidirectional blood flow, and group C with reverse blood flow. The cases were followed up to 6 months after birth and the relationship of prognosis and blood flow change in fetal ductus arteriosus was analyzed. Results：There were 31 in group A (45.6%), 25 in group B (36.8%), and 12 in group C (17.6%). It was found that the proportion of pulmonary stenosis and pulmonary atresia combined right ventricular dysplasia heightened with the increase of reverse blood flow in ductus arteriosus. Totally 39 cases were eventually followed up to 6 months after birth. In group A and B, the general situation was well after birth and preferable biventricular correction could be taken. While in group C, the prognosis was relatively poor after birth and early operation was needed, in addition, single ventricle palliative surgery was the major approach. Conclusions：Reverse blood flow in fetal ductus arteriosus is more common in fetuses with complex right heart malformations. Assessment of blood flow in fetal ductus arteriosus has great value in predicting prognosis of fetal right heart malformations.