Objective To investigate the effects of different tidal volume mechanical ventilation on pulmonary function and inflammatory factors in gynecologic laparoscopic surgery.Methods 45 patients undergoing gynecological laparoscopic surgery without lung disease,ASA Ⅰ-Ⅱ,aged 20-45 years old,weight 45-65 kg,operation time 2-3 hours,were randomly divided into A,B,C three groups,15 cases in each group.Mechanical ventilation with different tidal volume of the three groups,A group,B group and C group were 8mL/kg,9mL/kg,10mL/kg.Blood gas analysis was performed before anesthesia (T0),30 minutes (T1),(T2),PA-aDO2 (60 minutes) (T3),and 120 min (T4),respectively,and the peak airway pressure and mean pressure were recorded.IL-6,TNF-α and IL-10 levels in plasma by radial artery blood sampling were simnultaneously determined.Results Comnpared with A group,the concentrations of Ppeak and Pmean were increased in B group at T1-T4 (t =5.13,4.78,6.54,5.32 and t =7.54,4.88,5.37,4.95;all P ＜ 0.05),the concentration of Ppeak and Pmean in C group at T1-T4 increased (t =7.76,8.87,7.23,8.99 and t =6.42,7.38,7.62,9.86;all P ＜ 0.05).Compared with B group,the concentrations of Ppeak and Pmean were increased in C group at T1-T4 (t =4.76,5.87,4.23,3.99 and t =4.76,3.99,6.06,4.52;all P ＜ 0.05).Compared with A group,the A-aDO2 values of B group and C group were increased at T1,T2,T3 and T4 (t =5.32,5.48,4.88,5.69 and t =7.85,7.32,8.45,6.67;all P ＜ 0.05).Compared with B group at the same time point,the A-aDO2 value of C group increased at four times of T1-T4 (t =5.62,4.38,6.94,4.22,P ＜0.05).Compared with group A,the concentration of A-aDO2 in C group was higher than that in B group at the same time point (t =4.45,4.87,5.32,4.79 and t =7.68,7.59,7.44,8.38;all P ＜ 0.05).The levels of IL-6 and TNF-α in C group were significantly higher than those in the control group (t =4.78,5.56,7.62,8.03 and t =3.98,4.52,5.46,6.23;all P ＜ 0.05).Compared with T0,IL-6 and TNF-α concentrations AT T2-T4 in A group had no statistically significant differences (all P ＞ 0.05).Compared with B group,the levels of IL-6 and TNF-α in C group were significantly higher (t =4.58,4.99,6.53,4.77 and t =5.62,7.89,6.43,4.52;all P ＜ 0.05).Compared with T0,IL-6 and TNF-α concentrations at T2-T4 in A group had no statistically significant differences (all P ＞0.05).There was no significant difference in IL-10 concentration among the thrce groups.Conclusion Laparoscopic surgery according to the end tidal carbon dioxide partial pressure (PetCO2) ventilation frequency,8 mL/kg tidal volume mechanical ventilation has no effect on the IL-6,TNF-alpha,IL-10 and other inflammatory factors,mechanical ventilation tidal volume is more appropriate.