OBJECTIVE:To observe the effects of praeruptorin A for brachial plexus block anesthesia in patients receiving up-per extremity fractures surgery. METHODS:68 patients receiving upper extremity fracture surgery were randomly divided into trial group and control group with 34 cases in each group. Trial group was given praeruptorin A 0.2 mg/kg intravenously before brachial plexus block anesthesia,and control group was given equivalent volume of 0.9% sodium chloride injection. The anesthesia induc-tion time,the pain reflex disappearance time and postoperative recovery time were compared between 2 groups,and hemodynamic parameters and RPP were recorded in 2 groups before anesthesia (T0),immediately after anesthesia (T1),5 min after anesthesia (T2),10 min after anesthesia (T3),20 min after anesthesia (T4) . RESULTS:Anesthesia induction time,pain reflex disappear-ance time and postoperative respiratory recovery time in trial group were all significantly shorter than in control group,with statisti-cal significance(P<0.05). SBP,DBP,HR and MAP of trial group were lower than those of control group at T2,T3,T4,with sta-tistical significance(P<0.05). RPP of trial group was significantly lower than that of control group at T1,T2,T3 and T4,with sta-tistical significance (P<0.05). CONCLUSIONS:For brachial plexus anesthesia of upper extremity fractures surgery,preoperative application of praeruptorin A can shorten anesthesia induction time,pain reflex disappearance time and postoperative respiratory re-covery time,and reduce the fluctuation of hemodynamics.