Abstract: Objective To investigate effects of restrictive transfusion on the outcome of mitral valve replacement. Methods We selected 120 continuous patients of mitral valve replacement from June 2011 to June 2016. Based on the different blood transfusion strategy, the patients were divided into two groups: liberal blood transfusion group and restrictive blood transfusion strategy group. The blood routine test, liver and kidney function, coagulation function, full examination before blood transfusion, blood types, echocardiography and so on were examined when the patients were admitted to hospital, also the clinical data of perioperative patients were recorded, and blood transfusion volume, major complication and mortality were compared between the two groups. Results The transfusion volume of red blood cells decreased from (3.2±1.1) to (1.8±1.5) U with restrictive transfusion, the difference was statistically significant (P=0.01), while plasma volume increased from (325.7±96.5) mL to (385.2±86.2) mL (P=0.04). There were differences in major complications between the two groups (39.2% vs. 31.7%, P=0.04), especially for respiratory-related complications such as the proportion of using ventilator >24 h (P=0.03), total time using ventilator (P=0.03), lung infection rate (P=0.04). The restrictive transfusion group had better outcome with less cost of hospitalization. The mortality was not different (P>0.05). Conclusion Restrictive transfusion strategy reduces the incidence of major complications in patients of mitral valve replacement with less cost.