Abstract: Objective To investigate if the spectral entropy including response entropy（RE） and state entropy（SE） can predict movement at skin incision during sevoflurane anesthesia and to compare it with bispectral entropy（BIS）. Methods Twenty-two ASAⅠ-Ⅱ patients undergoing elective abdominal surgery were studied. They were allocated into movement group and non-movement group according to their response to skin incision. Anesthesia was induced with propofol,succinylcholine and fentanyl（iv）. After intubation,sevoflurane was inhaled and end-tidal concentration was maintained at 1.0MAC for 15min,then operation was begun without neuromuscular blockers. Sevoflurane end-tidal concentration was increased by 10% or decreased by 10% for the next patient when movement was detected or not detected. Each patient was simultaneously monitored with spectral entropy and BIS. Data were recorded at following time points:baseline values,60s and 30s before skin incision,45s and 120s after skin incision. Results No statistical difference was found in BIS index between the two groups（P＞0.05） but a statistical difference was observed in entropy index between two groups（P＜0.05）. RE and SE had threshold values of 76 and 75 with sensitivity/specificity of 89%/91% and 88%/92% for movement at skin incision respectively;RE and SE had threshold values of 65 and 64 with sensitivity/specificity of 88%/90% and 89%/91% for non-movement at skin incision respectively. Conclusion Entropy index can predict movement at skin incision during sevoflurane anesthesia.