In 40 patients with aortic regurgitation(AR), the incidence of reverse doming of anterior mitral leaflet was studied by 2-D echocardiography. Reverse doming could be indentified in 17 of 18 patients(94.4%)with severe AR, in 6 of 15 patients(14.3%)with mild AR. And in relation to the direction of regurgitant jet, reverse doming was noticed in 9 of 11 patients(82%) toward the center of left ventricular cavity.