Objective: To investigate the use of dexmedetomidine (Dex) in intratracheal intubation with fiberoptic bronchoscope (FOB) in thyroid surgeries under general anesthesia. Methods: Eighty ASA I~III patients (20 male, 60 female) aged 29~71 years weighing 45~80 kg scheduled for thyroid surgery under general anesthesia with tracheal intubation were randomly divided into Dex group(group D) and placebo group(group P)(n=40 each). Before induction, patients of the two groups received Dex(group D, 1 μg·kg-1, 4 μg·mL-1)or same volume of normal saline(group P) infusion for 15 min, respectively. After induction of anesthesia, orotracheal intubation was performed with FOB.BP, HR, and BIS were recorded noninvasively at 5 min after entrance to the operation room, the time before induction, the time before and just the time of tracheal intubation and at 1, 2, 3, 5, 10 min after tracheal intubafion. Hemodynamic response and complications of intratracheal intubation were observed. Results: The hemodynamic responses to intubation were significantly different between group P and group D (P<0.05). Less complications of intubation were observed in group D compared with group P(but P>0.05). Conclusion: Infusion of Dex before induction can prevent the hemodynamic responses to intubation with FOB, thus reduce relevant complications. ©, 2015, Chinese Journal of New Drugs Co. Ltd. All right reserved.