The target population are those patients with inoperable salivary gland derived primary or recurrent cancer, including local advanced primary salivary gland cancer which could not be resected completely; recurrent salivary gland cancer which could not be resected completely; T3/T4 tumor which could not tolerate surgery due to severe combined disease. The subjects would be divided into Iodine-125 radioactive seeds permanent interstitial implantation brachytherapy and intensity-modulated radiation therapy randomly. During the follow-up period, the efficacy and the safety index would be monitored.