Abstract: AIM To compare common endotracheal tube and double-lumen tube for one-lung ventilation undergoing minimally invasive direct coronary artery bypass(MIDCAB). METHODS Sixty patients aged 65-75 years(ASA Ⅱ or Ⅲ, Mallampati I-Ⅱ, cardiac functions Ⅱ or Ⅲ) were randomly divided into two groupscommon endotracheal tube group and double lumen endotracheal tube group, with 30 patients in each group. After anesthesia induction, patients in common endotracheal tube group were intubated with a single-lumen tube into the total bronchus of the right side and patients in double-lumen tube group were intubated with double-lumen tube of the right side. Before anesthesia induction, after intubation and postoperatively, systolic blood pressure(SBP), diastolic blood pressure(DBP) and heart rate(HR) were calculated. Before induction(T₀), 30 min after intubation(T₁), 30 min after thoracotomy(T₂) and 30 min after extubation(T₃), blood gas analysis was conducted and PO₂, PCO₂ and peak values were recorded. RESULTS Compared with those of the common endotracheal tube, SBP, DBP and HR of subjects with double-lumen endotracheal tube after intubation significantly increased. No significant difference in PO₂ and PCO₂ was found. Peak values of T₁ and T₂ in common endotracheal tube group increased significantly compared with those in double-lumen tube group(P<0.05) but were within the normal range. CONCLUSION Common endotracheal tube is superior to double-lumen tube for one-lung ventilation in elderly patients undergoing minimally invasive direct coronary artery bypass.