Objective:To evaluate the efficacy and safety of interstitial permanent low dose rate 125I seeds implantation under ultrasound guidance for local recurrent tumor ofhead and neck.Methods:64 consecutive patients totally 83 lesions underwent permanent implantation of 125 I seeds(from Jan.2004 to Oct.2014) under ultrasound guidance.Postoperative dosimetry was routinely performed for all patients.The actuarial D90 of the implanted 125 I seeds ranged from 100Gy to 160Gy (median:130Gy).The activity of 125 I seeds ranged from 0.3mCi to 0.8mCi (median: 0.69mCi).The total number of seeds implanted ranged from 3 to 89 (median: 20).The follow-up period ranged from 1 to 103.5 months (median: 14months).The survival and local control probabilities were calculated by the Kaplan-Meier method (SPSS 16.0).Results:Among all the 81lesions, totally response rate was 80.2%, 22lesions had complete remission CR (27%) and 43 had partial remission PR (53%).The 1-,3-and 5-year tumor control rates were all 75.2%, 73% and 69.1%respectively.The results ofcervical lymph node recurrence shows better than the recurrence or residue of primary head and neck neoplasm, with the local control of 5 year was 72.7% and 39.9% respectively.As of the date of follow-up, 22 of 64 patients still alive, The 1-and 3-,5-year overall survival rates were 57.4%, 31%, 26.6% respectively, with a median survival of 20 months.Grade 4 side effects of skin ulceration was seen in 2 patient;grade 1 or 2 skin reactions were seen in 11 patients (17%) who had received extemal beam radiation therapy before.Other severe complications s were not seen.Conclusions: Interstitial permanent implantation of 125 I seeds under ultrasound guidance is feasible, efficacious and safe for refractory head and neck metastasis or recurrence.