Abstract： Objective To summarize our experience and clinical outcomes of preservation of posterior leaflet and subvalvular structures in mitral valve replacement（MVR）. Methods We retrospectively analyzed the clinical data of 1 035 patients who underwent MVR in Beijing An Zhen Hospital from January 2006 to March 2011. There were 562 male patients and 473 female patients with their age of 37-78（53.84±13.13）years old. There were 712 patients with rheumatic valvular heart disease and 323 patients with degenerative valve disease, 389 patients with mitral stenosis and 646 patients with mitral regurgitation. No patient had coronary artery disease in this group. For 457 patients in non-preservation group, bothleaflets and corresponding chordal excision was performed, while for 578 patients in preservation group, posterior leafletand subvalvular structures were preserved. There was no statistical difference in demographic and preoperative clinical characteristics between the two groups. Postoperative mortality and morbidity, and left ventricular size and function were compared between the two groups. Results There was no statistical difference in postoperative mortality（2.63% vs. 1.21%, P =0.091）and morbidity （8.53% vs. 7.44%, P=0.519）between the non-preservation group and preservation group, except that the rate of left ventricular rupture of non-preservation group was significantly higher than that of preservation group（1.09% vs. 0.00%, P=0.012）. The average left ventricular end-diastolic dimension （LVEDD）measured by echocardiography 6 months after surgery decreased in both groups, but there was no statistical difference between the two groups. The average left ventricular ejection fraction (LVEF) 6 months after surgery was significantly improved compared with preoperative average LVEF in both groups. The average LVEF 6 months after surgery in patients with mitral regurgitation in the preservation group was significantly higher than that in non-preservation group （56.00%±3.47% vs. 53.00%±3.13%，P =0.000）, and there was no statistical difference in the average LVEF 6 months after surgery in patients with mitral stenosis between the two groups（57.00%±5.58% vs. 56.00%±4.79%，P =0.066）. Conclusion Preservation of posterior leaflet and subvalvular structures in MVR is a safe and effective surgical technique to reduce the risk of left ventricle rupture and improve postoperative left ventricular function．