Objective To study the characteristics of hemodynamic in middle-aged patients with essential hypertension or pre-hypertension.Methods 462 subjects were divided into three groups: the hypertension group,the pre-hypertension group and the normal group.A noninvasive hemodynamic monitoring system(LIFEGARD II) was used for detecting hemodynamic indices: SV,SVR,TFC and LCWI.Hemodynamic indices of three groups were compared with each other,and hemodynamic characteristics were further analyzed in the hypertension group.Results There were significant differences in SBP,DBP,PP,MAP,SVR,SV and LCWI(P0.05) between the hypertension group and the normal group,and in SBP,PP,MAP and SVR(P0.05) between the pre-hypertension group and the normal group.An abnormal SVR level existed in 58.8% of hypertension patients.Conclusions Various degrees of hemodynamic abnormality exist in hypertension/pre-hypertension patients.Noninvasive hemodynamic examination may provide help for individualized therapy of hypertension.