Object Diastolic function' s assessment is vital in order to produce information relevant to patients' functional class, management and prognosis. We sought to investigate diastolic dysfunction in essential hypertension (EH) with or without coronary heart disease (CAD) using color M- mode Doppler echocardiography and to study the relation between diastolic dysfunction and left ventricular mass index (LVMI) and geometry of LV, and to demonstrate partly the cause of increased cardiovascular risk of an echocardiographic pattern of LV geometry. Methods 36 normal subjects (Group Ⅰ) and 107 patients with essential hypertension (Group Ⅱ) were studied using color M- mode Doppler echocardiography. Four different LV anatomic adaptation to hypertension were identified by categorizing patients according to values of end-diastolic relative wall thickness (RWT) and LVMI. We measured the rate of propagation of peak early filling flow velocity (Vp), time delay (TD) of the peak early filling flow velocity from mitral tips to the apex and Vp/E. Results The geometry of LV was classified into four types according to the LVMI and RWT. The normal limits of LVMI and RWT were obtained from the upper limits of the 95 % confidence interval from mean of LVMI and RWT in healthy control group respectively, which were 115.2 g/m2 and 0.44. The definition of each type was as follows: Type Ⅰ (normal group): LVMI ≤ 115.2 g/m2 and RWT ≤0.44; Type Ⅱ (concentric remodeling): LVMI ≤115.2 g/m2 and RWT > 0.44; Type Ⅲ (eccentric hypertrophy): LVMI> 115.2 g/m2 and RWT ≤0.44; Type Ⅳ (concentric hypertrophy): LVMI >115.2 g/m2 and RWT > 0.44. Most parameters of diastolic function in each geometry type differed significantly from those in the control group, but the dif ference among each geometry type was not significant.When compared with type Ⅰ, there was a tendency thatTD was longer and Vp/E smaller in Type Ⅱ, Ⅲ and Ⅳgroups. The correlation between LVMI and Vp and TD had statistical significance (P < 0. 01); the correlation coefficients were - 0. 21 and 0. 29, respectively.Conclusions There is diastolic dysfunction in different LV geometry in patients with essential hypertension, even in patients with LV normal geometry there is diastolic dysfunction. LVMI has negative correlation to Vp, and positive correlation to TD. It may indicate that the greater the LVMI is, the worse the LV diastolic function.