Abstract: Objective: To explore the application effect of partial subvalvular structure preservation in mitral valve replacement in patients with mitral valve insufficiency.Methods: 86 patients with mitral valve insufficiency who underwent mitral valve replacement surgery in our hospital from January 2018 to January 2022 were selected as the study objects and were divided into control group (46 cases) and study group (40 cases) according to different surgical methods.The control group underwent surgical resection of mitral valve and subvalvular tendinous cords, while the study group underwent surgical resection of subvalvular structures.Perioperative indicators, inflammatory indicators and postoperative complications of the patients were compared between the two groups, and echocardiographic parameters were compared and analyzed between the two groups three months after surgery.Results: Compared with the control group, the time of aorta occlusion, cardiopulmonary bypass and postconcurrent time in the study group significantly increased, and the stay time in ICU was significantly shortened (P< 0.05).Three months after surgery, there were no significant differences in left atrial diastolic diameter (LADD), left ventricular ejection fraction (LVEF), left ventricular transverse diameter (LVTD) and left ventricular brachy-axis shortening rate (LVFS) between the two groups (P> 0.05).There were significant differences in Tei index, late diastolic regional mitral annular motion velocity (Ema), early diastolic regional mitral annular motion velocity (Eme), strain rate of the interventricular septum at the mitral annulus (SRS) and strain rate of the left ventricular wall at the mitral annulus (SRW) between the two groups before and after surgery (P< 0.05).The Tei index of the study group was lower than that of the control group (P< 0.05).Compared with the preoperative levels, the serum levels of IL-6, IL-10 and TNF-α of patients significantly increased after surgery (P< 0.05), but there was no significant difference between the preoperative and postoperative groups (P> 0.05).After 1-year follow-up, the complication rate of the study group (7.5%) was significantly lower than that of the control group (28.26%) (P< 0.05).Conclusion: Partial subvalvular structure preservation in mitral valve replacement can shorten the ICU stay time of the patients with mitral valve insufficiency, maintain their cardiac function, significantly reduce the Tei index, promote patient recovery, and reduce the postoperative complications.