Abstract: Objective: To investigate the effects of fentanyl on A-line ARX Index（AAI）;bispectral index（BIS） and hemodynamic response induced by orotracheal intubation,using the AAI as sedation "baseline".Methods: Thirty four ASA Ⅰ-Ⅱ（female） patients were equally randomized to receive either propofol infusion(30mg·kg^-1·h^-1) 2min preceded by 4μg/kg（fentanyl）（group PF） or preceded by comparable volume of normal saline（group P）.After loss of consciousness,and before（administration） of vecuronium 0.1mg/kg,a tourniquet was applied to one arm and inflated to 20kPa above systolic pressure.The trachea was intubated 5min after maintenance of AAI within 15 5.Gross movement within the 1st minute after orotracheal（intubation） was recorded;BIS,AAI and hemodynamic parameters including systolic arterial pressure（SAP）,diastolic arterial pressure（DAP） and heart rate（HR） were measured invasively pre-induction,before laryngoscopy,and 1,2,5min after （tracheal） intubation.（Results: Neither） within nor intergroup differences were found in BIS before or after intubation（P＞0.05）.AAI in group P increased significantly only at 1min after tracheal intubation（P＜0.05,vs pre-larngoscopy or group PF）,and decreased to pre-laryngoscopy level rapidly.The tracheal intubation caused a greater haemodynamic increase and higher incidence of movement in group P than those in group PF（P＜0.01）.Conclusion: At the sedation level of AAI at 15±5,fentanyl 4μg/kg attenuates haemodynamic reactions and prevents body movement induced by laryngoscopy and intubation.It also inhibits transient AAI increase after intubation.However,it has no significant effect on BIS.fentanyl;anesthesia,general;evoked potential,auditory