Objective: To investigate the feasibility of intravenous contrast sonography in the diagnosis of carotid atherosclerosis. Methods: Thirty-six patients with ICA, SCA or VA stenosis were investigated with ultrasound. Intima-media thickness (IMT) of these arteries and characteristics of plaques were measured in 36 patients before and after injection contrast agents, and the ratio of stenosis were calculated and contrasted with DSA. Results: After injection of the contrast agent, IMT was depictted more clear than before, and more plaques were discovered. The morphology and structure of plaques could be observed using contrast agents. In detecting occlusion of carotid artery, SCA and VA, compared with DSA, the sensitivity was 55.6% and 55.6% for CDFI and ultrasound contrast agent (USCA), while the specificity was 84.2%, 94.7% and the accuarcy was 75.0%, 82.0%, respectovely. Conclusion: USCA can be used as an effective and safe method in the diagnosis of carotid artery diseases.