73 age-matched hypertensive patients, 46 men and 27 women, were divided into the four groups according to left ventricular mass indexes (LVMI) and normal control groups were established correspondingly. Doppler and M-mode echocardiography were used to assess the systolic and diastolic functions of left ventricle (LV) and the alterations of heart construction. It was shown that when the LVMI increased slightly, the internal dimension and systolic function of LV had no significant change, but the diastolic function became abnormal and the left atrium enlarged. When the LVMI increased significantly, both the left atrium and left ventricle enlarged and the systolic and diastolic functions of LV were impaired. It is concluded that increase of LV mass may be present in the early stage of hypertension and left atrial enlargement is an early sign of left ventricular diastolic dysfunction, which occurs before systolic dysfunction in the patients with essential hypertension.