The purpose of this double-blind randomized clinical trial study, is to determine and compare the effect of local injection of bupivacaine and lidocain and epinephrine composition on post tonsillectomy pain. Case study samples, are 4-10 year- old children candidate for tonsillectomy, admitted in ENT ward in Imam Sajjad hospital. Samples with Inclusion criteria, will be chosen non-random and then will be placed in three groups by random blocks allocation and this continue until the samples are complete. Sample size is 29 patients in each group (a total of 87 people). Gathering Information will be done by direct observation, demographic check list and Wong-Baker pain scale. After Ethics committee of Yasuj University of Medical Sciences approval and parents informed consent, all patients will be under similar general anesthesia method. The method of cold knife dissection will be similar in all patients. 5 minutes before the surgical incision, in the first group, 2 ml of bupivacaine 0.125, in the second group 2 ml of 1% lidocaine combined and epinephrine 1: 200,000, will be injected locally in the bed and around the tonsils and tonsillectomy will be done. There is no intervention in Group 3. After surgery and transferring the patients to the ENT ward, pain will be measured 2 hours, 4 hours and 6 hours after surgery with Wong-Baker pain scale.