The purpose of this study is to investigate the effecacy of local ketamine, Morphin, and Lidocaine spray for controlling pain after tonsillectomy in children; in this clinical trial, 124 children with the age of 3-12 who selected for tonsillectomy will be divided to four group ; Ketamine group (k), Morphin group (M), Lidocain group (L), and Control group (C). The premedication, induction and maintenance of anesthesia in all of patient will be similar. At the end of surgery 0.5 mg/kg ketamine's spray in group (k), 0.05 mg/kg morphin's spray in group (M), 2 mg/kg lidocaine's spray in group (L), and normal saline spray in group C (8 puffs) will be used on the surface of surgery zone. After ex tubation and the entrance of patient to recovery room, pain scaling will be assessed for 1 hour (with 20 minute intervals) by personnel who were not aware of research methods. Pain control will be scaled with FLACC Pain Scaling System. In this system if anyone of patient in recovery room complained for severe pain, score 6 and more, will received pethidine 0.5 mg/kg for relief.