Abstract： Objective To investigate the diagnostic value of the real-time four-dimensional ultrasound imaging examination in the diagnosis of fetal malformations.Methods Four-dimensional ultrasound prenatal audio and video materials,1 008 cases of 12～20 weeks pregnant were retrospectively analyzed,and the dignostic value for the fetal malformation Was obser red by following-up.Results Four-dimensional ultrasound detection of fetal malformations in 26 cases,27 cases of confirmed postpartum fetal malformations,the rate was 96.3%,1 case of missed diagnosis.missed diagnosis rate was 3.7%misdiagnosis rate was 0.Conclusion The dynamic continuous four-dimensional ultrasound could show the activities of the fetus in uterus,diagnosis of most of the morphological structure of fetal malformations,reduced birth defects in children.