Laparoscopy is a useful technique for a diagnostic purpose of pelvic diseases in gynecologic patients, but it may be associated with many complications related to a steep Trendelenburg position and a usage of Trocar. It may also be developed that a large amount of CO2 insufflation into the peritoneal cavity causes respiratory acidemia and its related hemodynamic changes. To investigate the influence of the CO2, insufflation and the positional changes on the end-tidal CO2, tension (P>CO2), blood pressure and heart rate during laparoscopy in gynecologic patients, the authors observed the changes in PetCO2,heart rate, and blood pressure before the CO2, insufflation, at 1,3,5,7 and 10 minutes after the CO2, insufflation and at 2,5 and 10 minutes after the CO2, exsufflation respectvely under general endotracheal anesthesia with controlled ventilation (tidal volume 10 ml/kg, ventilatory rate 10 breaths/min). The results were as follows. 1) Pet>CO2 was increased until 10 minutes after CO2 insufflation. 2) PetCO2 was decreased at 2,5 and 10 minute after CO2 exsufflation but increased from the control value. 3) Heart rate was decreased at 1,3,5,7 and 10 minutes after CO2 insufflation and at 2,5 and 10 minutes after CO2 exsufflation from the control value respectively. 4) Systolic and diastolic blood pressures were increased after CO insuffiation and unti15 minutes after CO2 exsufflation. On the basis of the above results, because an increase of the PetCO2, and the hemodynamic changes occur during the laparoscopy using CO2 under general endotracheal anesthesia with controlled ventilation, it is recommended to monitor carefully PetCO2, heart rate and blood pressure to control adequately ventilation, blood pressure and heart rate.