Abstract： Objective To investigate the action of ligustrazine against oxidative damage for cellular immunoprotection in autologous blood transfusion.Methods Sixty patients scheduled for selective lumbar surgery (ASA Ⅰ to Ⅱ),with a pre-surgical estimation of blood loss ＞ 400 ml,were recruited.They were randomized into two groups,the study group and the control group (n=30 each).In the study group,Ligustrazine was given to patients by intravenous dripping at a dose of 2 mg/kg 30 mins before blood collection,and also added to the washing saline and heparinized saline solution (final concentration:0.005％) for processing of the collected blood.No Ligustrazine was given to patients or added to the washing saline and heparinized saline solution in the control group.The amount of blood loss and auto-transfusion were measured and recorded.Venous blood samples were collected from all patients before surgery (To) and at 1 hour,1 and 5 days after (T1,T2 and T3) and measured for the change in SOD activity and MDA level.Results In both groups,the SOD activity was significantly lower and MDA concentration was significantly higher at T1 and T2 as compared to the baseline values at To At T3 SOD activity in the study group was higher but remained a low level in the control group as compared with preoperation,while the MDA in the study group returned to preoperative level but was still higher than baseline in the control group.The SOD activity and MDA level were significantly different between two groups at all time points.(P＜0.05).Conclusion Ligustrazine has a role against oxidative damage in autotransfusion.