Ｏｂｊｅｃｔｉｖｅ　Evaluating the effect of different ventilation volume on gastric insufflation in patients undergoing laparoscopic cholecystectomy (LC) by ultrasonic monitoring.　Methods　Forty five cases of patients undergoing selective LC, aged 30-60 years old, ASAⅠorⅡ, BMI 19-24 kg/m2, were scheduled for selective operation under general anesthesia. They were divided into 3 groups (n=15) using a random number table: 6 ml/kg ventilation group (group V6), 7 ml/kg ventilation group (group V7), 8 ml/kg ventilation group(group V8). The volume control mode was used to ventilate 2 min after the induction of intravenous general anesthesia. Some respiratory parameters (SpO2, PETCO2) were recorded at the time of loss of consciousness (T0), after facemask pressure controlled ventilation for 30 s (T1), 60 s (T2), 90 s (T3), 2 min (T4) and after tracheal intubation (T5). The transverse section of the gastric antrum were measured respectively using ultrasound at T0 and T4.　Results　In group V6, SpO2 at T4-T5 was lower than value of T0 of same group and values at T4-T5 of the other two groups(P<0.05). PETCO2 at T3-T5 of group V6 was higher than value of T0 of same group and values at T3-T5 of the other two groups(P<0.05). The values of the cross-sectional antral areas after facemask volume controlled ventilation of group V8 were statistically significant larger than areas of group V8 before ventilation(P<0.05).　Conclusions　When the patient is induced by general anesthesia, the ventilation capacity of 7 ml/kg can guarantee the effect of ventilation and prevent the intake of gastric insufflation.