To observe the effects of different maintain doses of Dexmedetomidine on plasma cortisol and glucose during anesthesia recovery period in patients undergoing uvulopalatopharyngoplasty under sevoflurane inhalation anesthesia.In this prospective, randomized, double-blind study, 120 ASA I and II patients undergoing selective uvulopalatopharyngoplasty under general anesthesia were included. The patients were randomly allocated to three groups (n = 40): Dexmedetomidine low maintain dose group (D1), Dexmedetomidine high maintain dose group (group D2) and control group (group C). The Dexmedetomidine groups and control group were given Dexmedetomidine 1 microg/kg and normal saline in 20 ml within 15 min just before induction of anesthesia. Then Dexmedetomidine were maintained at 0.2 microg x kg(-1) x h(-1) and 0.7 microg x kg(-1) x h(-1) in group D1 and group D2 and were withdrawed 5 min before the end of operation, the same maintained speed of normal saline was given in group C. BIS value was maintained at 40-60 by adjusting the inhaled concentration of sevoflurane. Anesthetic was withdrawed 10 min before the end of operation. Thus, plasma cortisol concentration and blood glucose was needed to be detected just before anesthesia (T0), tracheal extubation (T1), 5 min after extubation (T2) and 15 min after extubation (T3). Duration of operation and anesthesia, consumption of sevoflurane, emergence time, extubation time, the occurrence of dysphoria, bucking and hypoxemia (SpO2 0.05).In the patients undergoing UPPP under sevoflurane inhalation anesthesia, Dexmedetomidine infused at 0.2 microg x kg(-1) x h(-1) maintains a stable hemodynamics without respiratory depression, alleviates stress response during extubation and reduces both the consumption of sevoflurane and the occurrence of dysphoria without prolonging emergence time and extubation time.