Abstract: ［Abstract］Objective The aim of this study was to explore the effects of volume controlled ventilation （VCV），pressure controlled ventilation（PCV）and pressure controlled ventilation-volume guaranteed （PCV-VG）on respiration and circulation in elderly patients undergoing thoracic surgery. Methods Thirty-six elderly patients who underwent thoracic surgery were enrolled in our study. Patients were divided into VCV， PCV and PCV-VG groups according to randomized design. The hemodynamic and respiratory data and the arterial blood gases had been recorded in the pre-operation，20 min，40 min，60 min after OLV and 20 min after the resumption of two lung ventilation. Results Compared with VCV group，Ppeak value was significantly lower in PCV and PCV-VG groups （P < 0.05）， and the difference was not found between the PCV and PCV-VG groups. PaO2 levels in PCV and PCV-VG groups were higher than that in VCV group after the point of OLV+40 （P < 0.05）. Comparison of PCV group， PaO2 in PCV-VG group was higher， but did not show a significantly improved during OLV（P > 0.05）. Conclusion Compared with VCV， the use of PCV and PCV-VG have significant advantages in the operative oxygenation and airway pressure for elderly patients undergoing OLV.