Objective：To study the causes of missed diagnosis and misdiagnosis on fetal ventricular septal defects, to reduce the rate of missed diagnosis and misdiagnosis. Methods：8066 pregnant women accepted fetal heart checking with echocardiography, the results were compared with postnatal echocardiography or necropsy specimens of the fetal heart after termination of pregnancy. Results：In 8066 pregnant women, 32 cases of ventricular septal defect were found, 16 cases were merged heart other malformations. 8 cases were missed diagnosis, 3 cases were misdiagnosed. Conclusion: Fetal echocardiography can diagnose ventricular septal defect explicitly, but there is existed missed diagnosis and misdiagnosis. So we consider the factors of missed diagnosis and misdiagnosis, improve the skills of checking fetal heart to reduce the rate of missed diagnosis and misdiagnosis.