The quantitative measurement and analysis of static and dynamic state of mitral annulus and mitral valve leaflet are important to the diagnosis and therapy of some heart disease. Thanks to the three dimensional echocardiography, it can indicate the complex inside structure of heart. Cooperating with Shanghai children medical center, we present the work of measurement and analysis of mitral valve, especially the mitral annulus and mitral valve leaflet by three dimensional echocardiographs in this thesi...