Ｏｂｊｅｃｔｉｖｅ　To evaluate the effects of different modes of ventilation of lung on operated side on early postoperative cognitive function in elderly patients undergoing radical surgery for esophageal carcinoma.　Methods　Seventy-two ASA Ⅰ or Ⅱ elderly patients of both sexes, aged 65-80 y, weighing 45-85 kg, scheduled for elective radical resection for esophageal cancer and were randomly divided into 3 groups (n=24) using a random number table: group A, group B and group C. After induction of anesthesia, the patients were intubated with double-lumen tube and one-lung ventilation was performed. During one-lung ventilation, the lung on the operated side was collapsed naturally in group A, positive pressure ventilation (fresh gas flow 2 L/min) was applied in the lung on the operated side in group B, and high-frequency jet ventilation (frequency 100 bpm, driving pressure 0.5 kg/cm2) was used in the lung on the operated side in group C. The blood samples were obtained before induction (T0), at the end of operation (T1), on 6 h (T2), 12 h (T3) and 24 h (T4) after operation for determination of plasma concentration of S100β protein, neuron-specific enolase (NSE), IL-6 and TNF-α. The Mini-Mental State Examination(MMSE) was used to test the cognitive function of the patients at T0, T4, 3 d (T5) and 7 d after operation (T6).　Results　Compared with the baseline value at T0, the plasma concentrations of IL-6, TNF-α, S100β protein and NSE in group A and group B were increased at T1-T4, the plasma concentrations of IL-6, TNF-α, S100β protein and NSE in group C were increased at T1-T3, the MMSE score in group A were decreased at T4-T6, the MMSE score in group B and group C were decreased at T4-T5(P<0.05). Compared with group A, the plasma concentrations of IL-6, TNF-α, S100β protein and NSE in group B and group C were decreased at T1-T4, the MMSE score in group B and group C were increased at T4-T6(P<0.05). Compared with group B, the plasma concentrations of IL-6, TNF-α, S100β protein and NSE in group C were decreased at T1-T4, the MMSE score in group C were increased at T4-T5(P<0.05).　Conclusions　Continuous positive ventilation and high-frequency jet ventilation of lung on operated side both can effectively improve early postoperative cognitive function, and the efficacy of high-frequency jet ventilation is better.