Abstract: Aim To investigate the relationship between the blood pressure variability （BPV） and left ventricular hypertrophy （LVH） in patients with essential hypertensive （EH） using 24 hour BP50 ambulatory blood pressure monitoring（ABPM） device. Methods Ninety three EH patients with and without LVH （47 males, 46 females, mean age 47.37±8 03 years） matched in sex and age, and compared with age matched normotensives（NT） controls（ n =46）. BPV was measured by the SD mean of systolic and diastolic pressures during 24 hour and circadian: 24 hSSD, 24 hDSD, dSSD, dDSD, nSSD and nDSD. Left ventricular mass index（LVMI） was evaluated by echocardiography. Results （1）The variability of systolic pressure during 24 hour and circadian was significantly higher than that of diastolic pressure in EH and normal controls. （2） 24hSSD,dSSD and nSSD were significantly higher in EH patients than that of normal controls （ P ＜0 05）.（3） In EH patients with LVH, the 24hSSD, dSSD, dDSD, nSSD and nDSD were significantly higher than that of EH patients without LVH and normal control（ P ＜0 05）. Conclusion This investigation suggests that the cardiovascular sympathovagal balance was impaired in EH patients, which is more significant in the EH patients with LVH than those without. Therefore, the BPV of EH patients may be associated with the severity of the degree of target organ damage.