Objective To investigate the effect pre‐injection of dexmedetomidine(Dex) on hemodynamics during intratracheal intubation period of general anesthesia with propofol or etomidate induction .Methods Eighty ASA Ⅰ - Ⅱ patients with elective surgery were randomly assigned to 4 groups:propofol group(P) ,P combined with Dex group(PD) ,etomidate group(E) and E com‐bined with Dex group(ED) ,20cases in each group .SBP ,DBP ,BIS and HR in 4 groups were recorded at the time points of before an‐esthesia after entering the operation room (T0 ) ,at l min after beginning for giving Dex(T1 ) ,10 min of infusing Dex(T2 ) ,3 min af‐ter anesthetic induction (T3 ) ,immediate intubation(T4 ) ,at l min after intubation(T5 ) ,3 min after intubation(T6 ) and 5 min after intubation(T7 ) .The SpO2 values and Ramesay scores were recorded at T 0 and T2 .Results HR at T2 and T3 in the group PD and Ed was decreased compared with those at T0 ,and lower than those in the group P and E(P<0 .01);DBP and SBP at T3 in the group ,PD and E were decreased compared with at T 0 (P<0 .05) ,while SBP and DBP in the group ED were higher than those in the group P and PD (P<0 .05) ,SBP and DBP in the group P were lower than those in the other 3 groups(P<0 .05) ;SBP and DBP at T4 in the group E were significantly higher than those in other 3 groups (P<0 .01);the blood pressure at T5 in the group E was significantly higher than that at T0 and in other 3 groups(P<0 .05);SBP and DBP at T6 and T7 in the group P and PD was de‐creased to the preoperativel levels (P<0 .05) .The SpO2 value at T2 in the group PD was lower than that at T0 (P< 0 .05);the Ramsay score at T2 in the group PD and ED was higher than that in the group P and E(P<0 .05) .The BIS value at T2 in the group PD and ED was lower than that at T0 ,which at T3 -T7 in the four groups was lower than that at T0 (P<0 .05) .Conclusion Pre‐injection of Dex can maintain the hemodynamic stability during endotracheal inbubation period by etomidate induction and also re‐duce the cardiovascular reaction caused by endotracheal intubation .