Objetive To investigate the clinical value of carotid computed tomography angiography(CTA) with 80kV lower tube voltage in carotid atherosclerotic plaques. Methods 56 patients underwent examinations of carotid artery with both CTA with 80kV lower tube voltage and color Doppler flow imaging(CDFI) within 7 days. CT dose volume index(CTDIvoI) and dose length product(DLP) was recorded to calculate the effective dose(ED). CT values of carotid artery of every patient were recorded. Compared and evaluated the concordance between 80kV low tube voltage CTA and CDFI in detecting carotid atherosclerotic plaques and assessment of stenosis. Results The mean values of CTDIvol,DLP and ED were (11.82±0.00)mGy,(295.04±43.93)mGy. cm and (1.74±0.26)mSv.The mean attenuation was (489.71±46.74)HU. There was no statistically significant (K＞0.60,P<0.05)between low tube voltage CTA and CDFI in detecting carotid atherosclerotic plaques and assessment of stenosis. Conclusion With 80kV lower tube voltage in carotid CTA, the radiation dose can be markedly reduced,and it is of great value in clinical application for the diagnosis of the carotid atherosclerotic plaque.