Aim: our study investigated the effects of IOC2 index monitoring on remifentanil dosage during desflurane anesthesia. We compared the intraoperative events and recovery characteristics between remifentanil adjusted by IOC2 monitoring guidelines versus remifentanil adjusted by clinical experience according to fluctuation in blood pressure and heart rate during desflurane anesthesia.　　Methods: 50 consecutive patients of ASA status I and II, aged 18-65 years, BMI 18-30 kg/m2 undergoing elective laparoscopic cholecystectomy under desflurane anesthesia were enrolled. The patients are randomized and allocated into 2 groups, group T (Trial group=25) and group C (control group=25) using sealed envelope method. The infusion rate of remifentanil was adjusted according to IOC2 monitoring guideline between30 to 50 in Group T whereas the infusion rate of remifentanil is adjusted by clinical experience according to fluctuation in blood pressure in group C. Remifentanil dose, adjustment frequency, infusion duration, intraoperative events, and quality of anesthetic recovery were compared between the two groups. The primary outcome was the dose of remifentanil.　　Results: Mean dose as well as the adjustment frequency of remifentanil was significantly higher in group T in compared with group C (0.1376±0.0268 vs0.0956±0.0223mcg/kg/min and 5.19±1.97vs1.7±0.57times/surgery, P＜0.05). Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) was not significantly different at the time of skin incision, at the gall bladder resection and at the time of skin suture between two groups (all p value＞0.05) however, IOC2 value at the time of skin incision, at the time of gall bladder resection and at the time of skin suturewas significantly different between two groups (all P value＜0.05). Although apparent differences in frequencies of hypotension, bradycardia, hypertension, the total number of patents with intraoperative events were found, they were not statistically different between two groups (all P ＞0.05). Both groups had similar voluntary eye opening time, extubation time, emergence agitation ,residual sedation 1 and 10 minutes after extubation, post-operative vomiting and NRS score （in PACU and 24 hours after extubation(all P＞0.05).　　Conclusion: IOC2 data was significantly high when remifentanil adjusted by clinical experience according to fluctuation in blood pressure and heart rate during the maintenance that expresses the deficit of analgesic component of anesthesia. The dose of remifentanil used according to IOC2（30-50)monitoring guideline utilized higher dose in compared with dose used by clinical experience based on blood pressure heart rate fluctuation however, the intraoperative events and recovery characteristics was not significantly different between two groups. Hence, application of IOC2 monitoring might be beneficial to the patients to adjust the analgesic depth during maintenance of anesthesia. Further, study to be done in large sample size and longer surgeries to investigate the optimal benefit of it in future.