To investigate the correlation between left ventricular hypertrophy and ambulatory blood pressure in patients with essential hypertension. 87 patients with essential hypertension were examined with 24 hour ambulatory blood pressure monitoring and echocardiography. There were positive correlation between left ventricular mass, left ventricular mass index and average systolic blood pressure, diastolic blood pressure, blood pressure loads, body mass index; negative correlation between left ventricular mass, left ventricular mass index and blood pressure decline rate of night, high density lipoprotein cholesterol. There were good correlation between left ventricular hypertrophy and high blood pressure, circadian rhythm of blood pressure. Control body weight and plasma lipids are also very important in reverse left ventricular hypertrophy.