Objective To evaluate the function and synchronization of left atrial in patients with chronic heart failure(CHF) by real-time three dimensional echocardiography (RT-3DE).Methods Thirty healthy controls and thirty-two patients with CHF were studied.The CHF were divided into group CHF1 with the normal of left ventricular filling pressure and group CHF2 with the elevated of that.From the volume-time curve of RT-3DE workstation,the maximum volume (LAVmax),the minimum volume (LAVmin),the volume before contraction (LAVp) of left atrial were acquired.Accordingly,the total,passive and active ejection fraction could be calculated.The synchronization parameters derived from RT3DE were the dispersion and maximum difference of time to minimum volume for left atrial segments (Tmsv- 16-SD,Tmsv 12-SD,Tmsv-6-SD,Tmsv- 16-Dif,Tmsv 12-Dif,Tmsv-6 Dif).The index of volume and time were corrected by the body surface area and interval of R-R,respectively.The correlation were analysed in them.Results ① All the index of volume before and after correction were gradually increasing from control to CHF2 group,but the LATEF,LAPEF and LAAEF were just the reverse,with all parameters had significant difference among total groups( P ＜0.01 ).②The synchronization parameters were significantly higher from control to CHF2 group( P ＜0.01 ).Comparing between two groups,no significant difference of the synchronization parameters were found between CHF1 group and CHF2 group ( P ＞ 0.05),except Tmsv-16-SD％ and Tmsv-16-Dif％ ( P ＜0.01 ).③The Tmsv-16-SD％ and Tmsv-16-Dif％ had a positive correlation with the index of volume and a negative correlation with the ejection fraction.The most significantly correlation parameters was LAVmaxI,with r =0.75 and P ＜0.01.Conclusions The function of left atrium are reduced in patients of CHF,there are dyssynchronization.The higher of the filling pressure of left ventricle,the lager of the dyssynchronization of left atrium.RT-3DE may paly important roles in the evaluation of function and synchronization of left atrium.