Objective: To investigate the effective dose of flurbiprofen for postoperative pain in patients undergone tonsillectomy.Methods: Fifty patients(ASAⅠ-Ⅱ) were randomly assigned into five groups.In Group F1~F4 patients received intravenous injection of flurbiprofen axeil 0.4,0.6,0.8 and 1 mg·kg-1 respectively and the contral group received 1μg·kg-1 fentainyl after surgery.The wake-up time,consciousness recovery time,extubation time were recorded.Pain intensity(PI) was assessed by color-analogue scales before the treatment and at 1h,2h,4h,6h and 8h after surgery in all of the patients.Results: The PI was significantly higher at each point in F1 and F2 compared to that in the control group;Compared to F4,the PI was signifficantly higher at 1,2 and 4h after surgery.Conclusion: The dose of 1mg·kg-1of flurbiprofen is safe and effective on postoperative pain in patients undergone tonsillectomy.