Abstract: Objective To evaluate the effect of different doses of dexmedetomidine nasal drip on the hemodynamics and postoperative sore throat in children undergoing pediatric tonsillar adenoid hypothermia plasma resection. Methods From December 2018 to October 2019,a total of 100 children aged 6-10 years who underwent tonsillar adenoid hypothermia plasma resection in the Affiliated Huaian No.1 People's Hospital of Nanjing Medical University were included and divided into four groups.Two minutes after surgery and extubation,different doses of dexmedetomidine （0.5μg/kgD₁ Group,n=25,1.0μg/kgGroup D₂,n=25,1.5μg/kgGroup D₃,n=25and 1ml of salineGroup C,n=25） were dripped through both sides of the nasal cavity.The heart rate,blood pressure and pulse oxygen saturation were recorded when the drug was dripped immediately （T₁）,and at 15 min （T₂）,30 min （T₃） and 60 min （T₄）,and the degree of throat pain during rest and swallowing at 6 hours （T₆）,24 hours （T₇）,48 hours （T₈）,and 72 hours （T₉） after the operation were also recorded. Results The effects of different doses of dexmedetomidine on mean arterial pressure and oxygen saturation were not statistically different between the four groups （P>0.05）.Saline solution with 1.5μg/kg dexmedetomidine （D₃ group） significantly reduced the heart rate of patients compared to the other 3 groups （P<0.05）.Under the effect of different doses of dexmedetomidine,the degree of sore throat in resting state increased first and then decreased over time,without significant difference when compared with normal saline group （all P>0.05）.At T₇ and T₈,the improvement of throat pain when swallowing in D₂ and D₃ groups were significantly higher than those of D₁ and C groups （P<0.05）,while there was no significant difference between the D₂ group and D₃ group （P>0.05）,which suggested that the two doses had similar effects on alleviating pharyngeal pain during swallowing,and the alleviating effects were better than those in the saline group and the D₁ group. Conclusion Saline solution with 1.0μg/kg dexmede-tomidine can significantly improve postoperative pharyngeal pain in children with tonsil adenoid hypothermia plasma resection,with satisfactory hemodynamic safety.