Laparoscopic cholecystectomy is a new surgical procedure which worldwidely applicated gallstone disease and is presenting now anesthetic challenges. The advantages of laparoscopic cholecystectomy are shorter hospital stay, more rapid retum to normal activies and less postoperative ileus, compared with open laparotomy. During the laparoscopic surgery to enable visualization of abdominal structures, pneumoperitoneum is made with CO2 insufflation but insufflation of CO2 into abdominal cavity has been reported several consequences. Hypercarbia, high peak airway pressure, cardiac arrhythmia which were all may result from CO2 insufflation. Also, increased intraabdominal pressure from the induced pneumoperitoneum can cause decreased venous return and may result in hypotension. To ascertain the cardiopulmonary effcts of the increased intraabdominal pressure by CO2 insufflation, a clinical study was performed in 80 patients who divided into four groups likes as control group (open cholecystectomy, number:No=20), group I (15 mmHg of pressure of pneumoperitoneum, No=20), group II (20 mmHg, No=20), group III (25 mmHg, No=20). We investigated the effect of CO2 insufflation to mean arterial pressure, heart rate, end-tidal CO2 partial pressure, mean airway pressure, and arterial blood gas components. The measurements were obtained from the time of skin incision(basic value) to 20 min every 5 min interval in all groups. The results are following, I. Mean arterial pressure significantly began to increase (p<0.05) at post-incision 5 min in control, group IIl & to decrease at post-incision 15 min in group compared with basic value. III. There were significant difference in pH between control and study groups, pH change were in normal ranges clinically. PaCO2 was significantly began to decrease (p<0.05) at post-incision 5 min in study groups compared with basic value, but still in normal acceptable ranges. IV. PaCO2 significantly began to increase (p<0.05) at post-incision 10 min in group II & at 15 min in group IIl compared with control group. Also PaCO2 significantly began to increase (p<0.05) at 5 min in group I, II & at 10 min in group III compared with basic value. V. PETCO2 significantly began to increase (p<0.05) at 10 min in group II & at 15 min in group III compared with control group. Also PETCO2 significantly began to increase (p<0.05) at 10 min in group I,II,III compared with basic value. VI. PAW significantly began to increase (p<0.05) at 10 min in group I,II,III compared with basic value. Conclusively, insufflation of CO2 into abdominal cavity during laparoscopic operation was minimal change in cardiopulmonary system and arterial blood gas value at below 20 mmHg intraabdominal pressure.