Objective · To assess the morphological changes of mitral valve geometry after mitral valve repair by using real-time 3D transesophageal echocardiography. Methods · The clinical data including 3D echocardiography of 36 patients undergoing mitral valve repair for mitral valve prolapse and 56 patients without mitral valve diseases were collected. Parameters of mitral annular and leaflet geometry were acquired and analyzed. Results · The ellipse index of the two-dimensional view (E2D), and non-planar leaflet angle (θNPA) were decreased, while other parameters were increased significantly in patients with mitral valve prolapse compared with controls before mitral valve repair. After repair, patients displayed larger θNPA, and still smaller E2D. Some parameters also get smaller, such as the anterior to posterior diameter of the mitral annulus, the anterolateral to posteromedial coaptation diameter, the minimum circumference of the three-dimensional view of the annulus, the minimum area of the two-dimensional view of the annulus, the exposed area of the anterior leaflet, inter-commissural diameter. Other parameters were not changed significantly. All parameters showed no significant difference between respect group and resect group in posterior valve prolapse before and after mitral valve repair. Conclusion · The repair procedure can restore the function of the mitral valve effectively. In view of the morphology, the geometry of the mitral valve annulus is still different from the normal apparently after the mitral valve repair, but the normal morphology of the leaflets can be regained. It seems to have similar curative effect morphologically for patients with posterior leaflet prolapse to have respect or resect strategy.