Cardiac output depends on the ability of systolic ejection and diastolic filling of the heart. M-mode echocardiography can provide accurate clinical assessment of left ventricular systolic and diastolic functions. To see whether there are changes of the left ventricular function in asymptomatic hypertensives and if any kind of dysfunction and whether any relationship between the pattern of the ventricular hypertrophy and type of ventricular dysfunction exists, the authors examined the systolic and diastolic function indices of the left ventricle in 50 normotensives and 88 hypertensives composed of 18 patients without left ventricular hypertrophy(group 1), 40 patients with disproportionate septal thickening (group 2) and 30 patients with concentric left ventricular hypertrophy(group 3). Obtained results were as follows : 1) Blood pressure & left ventricular mass index were increased significantly in each hypertensive group compared to normal control. 2) Ejection fraction & fractional shortening in the hypertensive groups were not different from the normotensive control group. 3) Left ventricular isovolumic relaxation time(A2D time) was prolonged in each hypertensive group, especially in group 3. 4) Left atrial emptying index (AEI) was decreased in each hypertensive group. 5) Left ventricular percent ventricular A wave (% VAW) was increased in all hypertensive groups. Above study suggested that the left ventricular diastolic function could be impaired in the hypertensives without associated systolic dysfunction, and the degree of the diastolic dysfunction was not much affected by the type of left ventricular hypertrophy, but the more prolonged A2D time in the concentric hypertrophy group.