Objective To observe the effect of Compound Notoginseng and Angelica Preparation（CNAP） on the carotid atherosclerosis（CAS） and plaque stability.Methods Totally 104 CAS patients were randomized into the CNAP group（39 cases）

atorvastatin group（34 cases） and control group（31 cases）.CNAP

atorvastatin and placebo was given to three group respectively for 1 year.High resolution ultrasound was used to observe the intima-media thickness（IMT） of carotid

the number of plaque and Crouse scores.Results The IMT and Crouse integral significantly decreased in the CNAP group and atorvastatin group after treatment（P<0.05）

and no obvious change was found in the control group after treatment（P>0.05）.There was no significant difference in IMF and Crouse between the two treated groups（P>0.05）

but the decrease was significant as compared with the control group（P<0.05）.The numbers of unstable plaque significantly decreased in the CNAP group and atorvastatin group after treatment（P<0.05）

with no significant difference between two groups（P>0.05）.There was no obvious change in number of unstable plaque in the control group after treatment.The difference in reduction of the number of unstable plaque between the control group and the treated groups was significant（P<0.05）.There were 3 cases of loose stools and 2 cases of nausea in the CNAP group after treatment

but the symptoms disappeared after drug withdrawal.Conclusion CNAP is effective for CAS with a significant role in the reversal of the unstable plaque.