Abstract: Objective To estimate the changes and clinical evaluation of left atrial（LA） function in patients using two-dimensional speckle tracking imaging（2D-STI） and real-time three-dimensional echocardiography（RT-3DE） in pre- and post-mitral valve replacement（MVR）. Methods Forty patients who expected to undertake MVR accepted echocardiography to estimate the LA function at pre-operation, 3 months and 1 year after operation. The LA maximum,minimum and pre-systolic volume（LAVmax, LAVmin and LAVp）, LA passive ejection fraction（LAEFp）, LA active ejection fraction（LAEFa） were measured by RT-3DE respectively, while STI was used to measure strain and strain ratio of left atrial anterior wall, posterior wall, side wall, inferior wall and atrial septal. The correlation analysis was performed between 2D STI and RT 3DE indexes. Forty control subjects provided normal states. Comparative analysis was made between the control and patients group. Results The Ss, mSRs, mSRe and mSRa of left atrial were lower than those of the control group. At 3 months after MVR, the Ss,mSRs and mSRe of left atrial were lower than those before MVR. At 1 year after MVR, the Ss, mSRs and mSRe of left atrial were higher than those before and at 3 months after surgery, but still lower than the normal control（P＜0.05）. The LAVmax, LAVmin and LAVp of patients with rheumatic heart disease were higher than those of the control group, whereas LAEF, LAEFp and LAEFa were lower than those of the control group. At 3 months after MVR, the LAEF and LAEFp were lower compared with before MVR（P＜0.05）, while at 1 year after MVR, the LAEFa and mSRa of patients had not changed significantly（P＞0.05）. mSRe was positively correlated with LAEFp, and mSRa was positively correlated with LAEFa. Conclusion RT-3DE and 2D-STI can evaluate left atrial function and are valuable to assess the efficacy of MVR.