Abstract: Abstract Objective：To evaluate the diagnostic potential of Real-time Three-Dimensional Echocardiography (RT3DE) in Ventricular Septal Defects (VSD). Methods：102 patients with VSD were diagnosed by RT3DE and Two-Dimensional Echocardiography (2DE), and the results were compared with surgical findings. Results：The defects were delineated objectively from many unique directions and angles by RT3DE that would not be available with 2DE, even simulated intraoperative visualization. The RT3DE views of VSD including the anatomical shape, positon, size and spatial relations could be appraised in their nature. The VSD maximum diameters obtained from RT3DE was 1.02±0.14 cm, from 2DE was 0.86±0.28 cm, from surgical findings was 1.05±0.36 cm. There was no statistical difference between measurements made by RT3DE and those obtained at surgery, there was a statistical difference between 2DE and RT3DE or surgical findings. Conclusion：Compared with the 2DE, RT3DE could display the true stereoscopic views of VSD, and provide better quantitative evaluation of the size, and lead to an improved understanding of the pathophysiology of VSD. RT3DE has important applied potentiality in clinical field.

Key words: Echocardiography, Real-time three-dimensional, Ventricular septal defect