Abstract: Objective To evaluate the effect of tourniquet on blood loss during total knee replacement. Methods Forty-seven patients（5 males and 42 females） at the mean age of 62.68 years,who underwent total knee replacement in our hospital from September 2009 to May of 2010,were retrospectively analyzed.Their hemoglobin and erythrocytes,drainage volume from knee lumen after operation,blood loss during operation,tourniquet-used time,and total operation time were recorded to compare the effect of tourniquet on blood loss. Results No significant difference was observed in hemoglobin,erythrocytes,blood loss during operation,drainage volume after operation,and total operation time after tourniquet was used.The tourniquet used in enclosure from femoral osteotomy to capsule could significantly reduce the time of using tourniquet. Conclusion The tourniquet used in enclosure from femoral osteotomy to capsule does not result in more blood loss during operation and exacerbate anemia after operation.