Objective:To explore the clinical values of 131I whole-body scan (131I-WBS) and 131I single photon emission computed tomography/computed tomography (131I-SPECT/CT) on the management of patients with differentiated thyroid carcinoma (DTC) after 131I therapy,respectively. Methods:After 3~5 days 131I therapy,48 DTC patients underwent 131I-WBS and 131I-SPECT/CT. The imaging features and clinical values of 131I-WBS and 131I-SPECT/CT were comparatively analyzed. Results:The patients had totally 48 131I-WBS and 60 131I-SPECT/CT. 145 foci were observed by 131I-WBS,including 34.3% of foci localized in the thyroid bed,60.5% of malignant lesions,and 5.2% caused by nonthyroid physiologic or benign uptake or a contaminant. There were 23 additional metastases detected by 131I-SPECT/CT. Futhermore,there were 20 patients whose 131I-WBS showed 65 inconclusive lesions. Precise localization and characterization by 131I-SPECT/CT fusion images were 65(100 %) and 61(94 %) of the 65 foci,respectively. 131I-SPECT/CT fusion images were considered to be of much benefit to 18(37.5%) of 48 patients. Changes of therapeutic plans happened to 8(44.4%) of 18 patients. Conclusion:131I-WBS should be routinely performed in the management of patients with DTC after 131I therapy. If 131I-WBS images were inconclusive or inconsistent with the clinical manifestations,131I-SPECT/CT must be required to increase the diagnostic accuracy and modulate therapeutic plans.