Ｏｂｊｅｃｔｉｖｅ　To evaluate the effect of dexmedetomidine(Dex) as an adjuvant to general anesthesia on perioperative hemodynamic fluctuation in pediatric patients undergoing craniotomy.　Methods　This was a prospective, randomized, double-blind and placebo-controlled pilot study. Fifty-two pediatric patients(aged 4－12 years) with intracranial tumor scheduled for craniotomy were randomly assigned into two groups(n=26). After anesthesia induction, one group of patients (Dex group) received a loading dose of Dex (0.5 μg/kg iv infusion for 15 min), followed by a continuous infusion at a rate of 0.5 μg·kg-1·h-1 till the end of the operation, another group of patients(control group) received the same volume of normal saline with the same procedure. Hemodynamic parameters, including SBP, DBP and HR, were monitored throughout the operation.　Results　 Although 15 min Dex infusion did not cause siginificant changes in SBP and DBP(P>0.05), it maintained SBP and DBP at higher levels than control group[SBP: Dex group, (109±12) mmHg(1 mmHg=0.133 kPa), control group, (101±13) mmHg. DBP: Dex group, (68±13) mmHg, control group, (61±12) mmHg](P<0.05). At 5 min and 10 min after extubation, HR in the Dex group were significantly lower than those in the control group[After extubation: 0 min, (94±18) bpm vs (113±21) bpm. 5 min, (95±19) bpm vs (111±18) bpm. 10 min, (94±17) bpm vs (110±18) bpm](P<0.05). The dose of propofol used for general anesthesia was significantly lower in the Dex group than that in the control group[(852±346) mg vs (1 176±434) mg](P<0.01). SBP, DBP and HR at other timepoints, recovery time, and incidence of adverse effects were not significantly different between the two groups（P>0.05）.　Conclusions　Dex attenuated the intraoperative hemodynamic responses and dose of drugs for general anesthesia in pediatric patients undergoing craniotomy, without prolonging recovery time or increasing the incidence of adverse events.