The mitral valve is not a simple but a complex structure, mitral valve complex. This complex is composed of mitral orifice, annulus, valve leaflet, chordae tendineae and papillary muscles. There were many controversies about this structures. We studied mitral valve complex in 63 cases of normal Korean adults, such as the circumference of mitral annulus, the intercommissural diameter, height and breadth of the cusps, including commissure, the ratio of rough to clear zone, breadth of the achordal zone, the number of scallops of posterior cusp, the number, length and the pattern of arrangement of the several types of chordae, the number and morphological characteristics of papillary muscles.