To investigate the correlation of polymorphism of angiotensin-converting enzyme (ACE) genes with left ventricular hypertrophy in essential hypertension, 151 patients with essential hypertension were studied. ACE genotypes were determined by PCR technology and diastolic left ventricular diameter (DLVd), systolic left ventricular diameter (SLVd), interseptal ventricular thickness (IVS), and left ventricular posterior wall thickness (LVPW) were scanned by echocardiography. Left ventricular mass (LVM) and the left ventricular mass index (LVMI) were calculated from echocardiographic findings. Results revealed that DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the DD genotype group were 49.9±5.6mm, 30.5±6.5mm, 11.2±1.6mm, 11.7±1.5mm, 259.5±62.1g, 92.7±23.5g/m², respectively. DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the ID genotype group were 8.9±5.3mm, 31.5±5.2mm, 11.4±1.7mm, 11.9±1.6mm, 261.3±70.3g, and 94.9±25.8g/m², respectively, and DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the II genotype group are 48.9±5.5mm, 31.8±6.5mm, 11.1±1.9mm, 11.5±1.8mm, 250.8±82.5g and 90.8±30.1g/m² respectively. There was no significant difference between the ID, DD and II genotype groups as regards DLVd, SLVd, IVS, LVPW, LVM, and LVMI (p>0.05). These findings indicate that there is no association between the ACE gene and left ventricular hypertrophy in essential hypertension occurring in the Chinese population. (Hypertens Res 2000; 23: 261-264)