Objective: To compare the effects of thoracic epidural administration of lidocaine on hemodynamic and arousal responses of double lumen tracheal intubation during induction of anesthesia. Me-thods: In the study, 40 patients with American Society of Anesthesiologists (ASA) physical statuses Ⅰ-Ⅱ,aged 19-66 years,scheduled for elective thoracic surgeries under general anesthesia requiring orotracheal intubation were allocated to either the double-lumen endobronchial intubation (T group) or double-lumen endobronchial intubation after epidural administration of lidocaine (E group). After an intravenous anesthetic induction, the orotracheal double-lumen intubation was performed using a Macintosh direct laryngoscopy (MDLS),respectively. Invasive blood pressure (BP),heart rate (HR) and bispectral index (BIS) were recorded before and after anesthetic induction,immediately after intubation and 5 minutes after intubation with 1-minute interval and the intubation time also noted. The rate pressure pro-duct (RPP) was calculated.Results: After anesthetic induction,BP and RPP in the two groups decreased significantly compared with their preinduction values. In comparison with their postinduction values, the orotracheal intubation in the two groups caused significant increases in BPs, HRs and RPP. In comparison with their preinduction values, BPs decreased significantly in E group, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) increased significantly and lasted for 1 min in T group. The HRs of both groups after intubation were significantly higher than their baseline values,and increased in HR and lasted for 1 min and 4 min in E group and T group, respectively. SBP, DBP, MAP, HR and RPP after intubation in T group were significantly higher than those of E group during the observation period. The values of BIS were similar between both the groups. In T group, the incidences of SBP percent increased>30% of the baseline value and RPP more than 22 000 were significantly higher than in E group. None of the patients in group E had SBP more than 130% of the baseline value and RPP more than 22 000.Conclusion: During double-lumen endobronchial intubation, epidural administration of lidocaine can provide less hemodynamic response and similar arousal response.