Abstract: Objective:To evaluate the effect of dexmedetomidine(DEX) on the hemodynamic changes induced by scalp infiltration with epinephrine-lidocaine mixture during craniotomy under general anesthesia.Methods:One hundred patients with intracranial tumor were randomly and equally divided into five groups, and each group was infiltrated 16 ml of epinephrine-lidocaine mixture of different concentrations:group A 2.5 μg/ml, group B 5 μg/ml, group C 7.5 μg/ml, group D 10 μg/ml and group E 7.5 mg/ml received intravenous pumping of DEX 1 μg/kg before scalp infiltration.The hemodynamic changes were recorded before anesthetic induction, infiltration, using DEX and 5 min after infiltration.Results:The number of the patients with declined mean arterial pressure(MAP) over 20% was greater in group C than that in group D(P<0.05).The MAP and systolic blood pressure(SBP) had no statistically significant difference among the five groups in T_{base values} and T₀(P>0.05).The SBP in group E on T₁, T₂, and T₇～T₁₀ was higher than that on T₀(P<0.05 to P<0.01);and compared with group C, the SBP on T₁～T₅, T₈～T₉, the diastolic blood pressure(DBP) on T₁ and T₃～T₁₀, and the MAP on T₁～T₁₀ had significant differences(P<0.05);the DBP, MAP and heart rate of group E had no significant differences at different time-points(P>0.05).Conclusions:The epinephrine-lidocaine mixture used for scalp infiltration could reduce the arterial pressure of the patients undergoing craniotomy;intravenous pumping of DEX could attenuate the hypotension degree induced by scalp infiltration of epinephrine-lidocaine mixture.