Objective: To discuss hemodynamic parameter criteria and their accuracy in diagnosing carotid stenotic lesions in patients with color Doppler flow imaging (CDFI). Methods: The peak systolic velocity (PSVCCA, PS VIC, PSVDIS) and end-diastolic flow velocity (EDVICA, EDVDIS) in 416 patients with carotid stenotic lesion on distal common carotid arteries, stenotic segments of the internal carotid artery, and stenotic distal arteries (832 arteries) were detected by using CDFI. Using the results of digital subtraction angiography (DSA) as criteria, PSVICA/PSVCCA, PSVICA/ PSVDIS, EDVICA/EDVDIS and receiver-operator characteristic (ROC) area under the curve were calculated. The sensitivity, specificity and overall accuracy of the above parameters under the different values were compared, and they were also compared with the recommended CDFI diagnostic criteria in the previous literatures. Results: The parameter criteria for diagnosing 50%-69% ste nnoses were in order of PSVICA ≥ 155 cm/s, EDVICA ≥60 cm/s, PSVICA/PSVCCA ≥2.0, and PSVICA/PSVDIS ≥1.6; the parameter selection of 70%-99% stenoses were PSVICA ≥ 220 cm/s, EDVICA ≥ 100 cm/s, PSVICA/PSVCCA ≥ 3.5, and PSVICA/PSVDIS ≥ 3.5. The combination of PSVICA, EDVICA, PSVICA/PSVCCA or PSVICA, EDVICA, and PSVICA/PSVDIS improved the diagnostic accordance rate of 50%-69% or 70%-99% carotid stenoses and DSA; they were 95.5%, 92.9%, 96.4%, and 93.9%, respectively. The accuracy (91.1%) of PSVICA/PSVDIS odds for 70%-99% carotid stenotic lesions was higher than PSVICA/PSVCCA. Conclusion: PSVICA, EDVICA, PSVICA/PSVDIS, and PSVICA/ PSVCCA are the accurate hemodynamic parameters in assessing the severity of carotid stenosis, and the combination of these parameters may improve the accuracy of diagnosis.