Lung metastases are more common in metastatic disease in differentiated thyroid carcinoma (DTC). Because of its insidious onset and slow development, clinical diagnosis is relatively difficult. Some possible diagnostic methods for detecting the lung metastasis of DTC including serological examination, radionuclide imaging and other medical imaging patterns are discussed in this paper. The progress and the current situation about investigation of those modalities which are in the early diagnosis, recurrent and clinical evaluation for the lung metastasis of DTC are briefly reviewed. Therefore, it is expected to promote DTC with lung metastasis to a higher diagnostic level.