Recently, laparoscopic cholecystectomy becomes a favorite surgical treatment of cholelithiasis instead of traditional open cholecytectomy. The reasons include small wound, small pain and short hospital-stay. But it also has disabvantages by pneumoperitoneum made of carbon dioxide insuffulation. We attempted to investigate the effect on hemodynamics, arterial blood gas parameters and pulmonary function of each surgical technique-laparoscopic(Group I) vs open cholecystectomy(Group II). We randomly selected realative healthy 30 patients for each group and baseline arterial blood gas and pulmonary function test were measured. During the operative proeedure, hemodynamic parameters(blood pressure and heart rate) were measured by 5-minute interval. Postoperatively, arterial blood gas and pulmonary function test were measured. The results are following; 1) In group I, blood pressure was increased to l14.2±18.0mmHg significantly(p<0.01) compared to preoperative value 101.4±21.5 mmHg. Heart rate was not shown significant change in both technique groups. 2) PaO2 was significantly decreased to postoperative 24hr value 82.2±15.8mmHg in group II and 82.3±19.4 mmHg in group I compared to preoperative 24hr value 98.7±14.8 mmHg and 94.4±ll.3mmHg, respectively. There was no significant difference of PaCO2 of between two groups. pH was significantly increased to postoperative 24hr value 7.42±0.02 in group II compared to preoperotive 24hr value 7.39±0.03 but no significant change in group I compared to preoperative 24hr value 7.39±0.03. 3) In group I, FVC and FEV1 were decreased preoperative 24hr value 77.9% and 81.1% to postoperative 24hr value 61.1% and 62.3%, respectively. But in group II, FVC and FEV1 were decreased more significantly, compared preoperative 24hr value 90.8% and 95.6% with postoperative 24hr value 59.4% and 58.6%. FEV1,/FVC value was not changed in two groups. 4) Postoperative analgesics requirement was 53% in group I, 80% in group II at the day of surgery. Also frequency was 1.8 in group I, 2,4 in group II at the day of surgery. 5) Mean Operation time was 43 min in group I, 52 min in group II and mean hospital days were 6 days in group I, 12 days in group II. Conclusively, in case of group I, blood pressure change was more labile than group II. But postoperative pulmonary function derangement, requirement of analgesics and hospital day were reduced in case of group I.