OBJECTIVE： To observe the effects of praeruptorin A for brachial plexus block anesthesia in patients receiving upper 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 induction 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 disappearance time and postoperative respiratory recovery time in trial group were all significantly shorter than in control group， with statistical significance （P＜0.05）. SBP， DBP， HR and MAP of trial group were lower than those of control group at T2， T3， T4， with statistical significance （P＜0.05）. RPP of trial group was significantly lower than that of control group at T1， T2， T3 and T4， with statistical 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 recovery time， and reduce the fluctuation of hemodynamics.