To explore therapeutic effect of Huanglian Jiedu Decoction in carotid atherosclerosis(CAS)，effects on inflammatory indexes，blood lipid metabolism and vascular endothelial function of patients，and mechanism of Huanglian Jiedu Decoction in the treatment of CAS patients，and to provide reference for further optimization of CAS treatment.Methods:A total of 148 cases of CAS patients in the Xi'an Hospital of Traditional Chinese Medicine from January 2016 to January 2018 were selected as research objects，and they were numbered according to the order of entering groups.The odd number was set as the control group(74 cases)，and the even number was set as the observation group(74 cases).The 2 groups of patients were treated with conventional western medicine for CAS，and the observation group was also treated with modified Huanglian Jiedu Decoction according to syndrome differentiation.Serum inflammatory indicators including hypersensitivity C reactive protein(hs-CRP)，interleukin-6(IL-6）and tumor necrosis factor(TNF-ɑ)，level indicators of blood lipid metabolism including cholesterol(TC)，triglyceride(TG)，high-density lipoprotein cholesterol(HDL-C）and low density lipoprotein cholesterol(LDL-C)，and functional indicators of vascular endothelial cells including nitric oxide(NO)，endothelin(ET)，vascular endothelial growth factor(VEGF）in the 2 groups were compared before and after the treatment.Internal diameter of the carotid artery，carotid intima-media thickness(IMT)，volume of the largest plaque，number of plaque，adverse drug reactions and toxic and side effects in the 2 groups were compared before and after the treatment.Results:1）After the treatment，the levels of serum hs-CRP，IL-6 and TNF-ɑ in the 2 groups were significantly decreased than those before the treatment，and those in the observation group were lower than those in the control group(P<0.05). 2）After the 2 groups of patients completed the treatment，the TC，TG and HDL-C were lower than those before the treatment，and those in the observation group was lower than those in the control group; the LDL-C was higher than that before the treatment，and that in the observation group was higher than that in the control group(P<0.05). 3）After the treatment，the serum NO，ET and VEGF in the 2 groups were significantly higher than those before the treatment，and those in the observation group were higher than those in the control group(P<0.05). 4）After the 2 groups of patients completed the treatment，the internal diameter of the carotid artery，the IMT，the maximum plaque volume and the number of plaque in the carotid artery were significantly lower than those before the treatment.And those in the observation group were lower than those in the control group(P<0.05). 5）There was no significant difference in the rate of adverse drug reaction between the 2 groups during the treatment(P>0.05).Conclusion:Huanglian Jiedu Decoction can reduce indicators like the number and size of carotid atherosclerotic plaque and the internal diameter of the carotid artery in CAS patients by improving the blood lipid metabolism，inflammatory state and vascular endothelial function of CAS patients.It can effectively improve the carotid atherosclerosis of CAS patients with high safety and high clinical value.