Objective To define the mechanical features of mitral annulus at various sites,and to investigate the specific mechanics characterization at different mitral annulus sites in evaluation consequences of left ventricular function by dual pulse-wave Doppler (DPW) technology.Methods The DPW spectrums were obtained at lateral and aboral interval,anterior and inferior and posterior mitral annular from 112 normal adults.The peak systolic velocity (Sm),peak early diastolic velocity (Em),peak late diastolic velocity (Am),the beginning time of the peak and the time to peak were measured,and E/A,Em/Am,E/Em,left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were computed.Results 1)Sm,Em,Am and Em/Am measured in the free wall annulus were significantly greater than measured in the interval annulus of mitral annular sites.However,E/Em was opposited (P ＜ 0.05).Sm of the posterior wall mitral annulus accelerated frist and experienced shortest duration in all the mitral annular sites (P ＜ 0.01).There were no significant differences of Em time parameters among different mitral annulus sites.Am of the beginning time and peak time in the free wall annulus were significantly longer than that in the interval annulus of anterior mitral annular sites.However,the acceleration time was opposited(P ＜0.05).2) Sm was correlated with LVEF and LVFS (r =0.243 and r =0.227,P ＜0.01) only at the posterior mitral annular site,Em/Am of anterior and posterior wall mitral annulus had the highest correlations with mitral orifice flow E/A(r =0.545 and 0.545 respectively,P ＜ 0.01).Conclusions There are significant differences among the mechanics patterns at different mitral annulus sites in normal adults.The mechanics characterization at different mitral annulus sites have different conclusions of left ventricular function.