Abstract: Na⁺/I^- symporter is a membrane glycoprotein that catalyzes the active accumulation of I^-. The abnormality of NIS gene will lead to thyroid disease. We had succeeded in transfecting the Na⁺/I^- symporter into tumors for radioiodide concentration. However, the effective half life is too short to acquire therapeutic dose. So we should research into prolonging the effective half-life and increased effective transfection.