Abstract: Objective To investigate the effect of dexmedetomidine on oxidative stress and inflammatory reaction in patients with orthopaedic trauma surgery. Methods Total 82 cases of trauma patients undergoing elective surgery in our hospital between January,2015 and April,2016 were divided into study group (n=40) and control group (n=42).All patients received Inhalation-intravenous general anesthesia.The study group was given intravenous infusion of dexmedetomidine 1 μg/kg before the induction and continuous infusion of 0.2 μg/(kg·h) dexmedetomidine,while the control group was given the same amount of normal saline.HR and MAP were recorded at T0(entering the operating room),T1(tracheal intubation was over),T2(the operation lasted for 60 min),T3(the end of the operation) and T4(extubation).The levels of SOD,cortisol,MDA,TNF-α and IL-6 at T0,T2,T3,T5(postoperative 8 h) and T6(postoperative 24 h) were compared between the two groups. Results At T1-T4,the levels of MAP and HR in the study group were significantly lower than those in the control group and the difference was statistically significant (P<0.05).At T3,T5 and T6,the level of SOD in the study group was significantly higher than that in the control group,while the levels of cortisol,MDA,TNF-α and IL-6 were significantly lower than those in the control group,the difference was statistically significant (P<0.05).The operation time and intraoperative blood loss were compared between the two group,the difference was not statistically significant (P>0.05).The time of awaking from anesthesia in the study group was significantly shorter than that in the control group,the difference was statistically significant (P<0.05). Conclusion Dexmedetomidine can maintain the stable hemodynamics of patients with orthopaedic trauma surgery,significantly reduce the oxidative stress response and inflammatory reaction of patients.