Abstract: Fusion image of SPECT and CT on thyroid neoplasms has converged ascendancy of anatomic and functional image, overcome the inherent limitations of conventional single image modalities,and could provide good anatomic and functional data. It has distinct ascendancy in precise localization and qualitation of neoplasms presurgically, in monitoring the response to treatment and for detection recurrence or metastases. Moreover, it is cheap when compared with PET-CT, and can be of great value in clinical application.