Objective To evaluate the clinical value of color doppler flow image (CDFI) and three-dimension color power angiography(3D-CPA) in the diagnosis of thyroid nodules. Methods A total of 62 pathologically confirmed thyroid nodules of 30 patients were analyzed. All the patients underwent ultrasound examination and operation in the Second Affiliated Hospital of Harbin Medical University between January, 2008 and May, 2009. Both CDFI and 3D-CPA were performed before the operation. All the nodules were divided into three groups including nodular goiters, thyroid adenomas and thyroid cancers according to the pathological results. The hemodynamic features and the vascular morphology characteristics of nodules in different groups were compared. Results 3D-CPA showed that blood vessels of nodular goiters commonly distributed surrounding the mass and the inner vessels were thin and regular, thyroid adenomas were bulb-shaped and netted structure, and malignant thyroid nodules displayed distorted and irregular distributed vessels. Peak systolic velocity (PSV)of the three groups were (39.43±11.17a), (46.39±12.98) and (65.17±9.23)cm/s, respectively. Resistance index(RI) of the three groups were (0.32±0.08), (0.41±0.06) and (0.69±0.07)cm/s, respectively. Both PSV and RI in malignant thyroid nodules were higher than in nodular goiters and in thyroid adenomas and the difference were statistical significant (all P < 0.05). The blood flow grade of malignant nodules was also higher in malignant nodules than in other two groups(χ2 = 17.11, 12.79, 23.05, 15.41, P< 0.01). Conclusions CDFI and 3D-CPA could visually demonstrate the characteristic and distribution of the inner and outer blood vessels, display the vessels structures, and they are benefit the differential diagnosis of thyroid nodules.