Abstract: Although radioactive seed interstitial implantation had been used for a long time, the relationship between the physical, biological characteristics, the clinical dose and curative effect, complications had been deeply discussed for decade. Treat the tumor by seed interstitial implantation technology, implanting the radioactive seeds into malignant tumor tissues well-distributed and regularly according to the radiotherapy plans, then the tumor receive higher doses of radiation, while the normal tissue get less or no injure. This seed implanted technology is used for treatment tumors that hard to surgical resection, could not reached complete excision and surgery residual, and implant seeds in tumor edge avoid recurrence and metastasis. Radioactive seed implantation technology for cancer developed rapidly in 10 years, more than 600 hospitals carried out the technology in China recently, and the technology indication will expand to the solid tumors origin from organs such as liver, lung, esophagus, pancreas, rectum, prostate gland, thyroid, head, facial, nasopharynx and so on.