Abstract： Objective To study the relationship between dyslipidemia and carotid artery atherosclerosis in patients with metabolic syndrome(MS).Methods 918 patients with MS were divided into three groups:normal total cholesterol(n=502,N-TC),isolated hypercholesterolemia(HC)(n=190)and mixed HC(n=226,M-HC).The N-TC group was divided into four subgroups:normal triglyceride(N-TG)plus normal high density lipoprotein(N-HDL)(n=112),high TG(n=61 patients),low HDL-C(n=186),mixed group(n=143).Serum lipid profile and ultrasonography for carotid artery were examined.Results Both carotid intima-media thickness(IMT)and number of plaque were higher in isolated and combined HC groups than in normal cholesterol group(P<0.05).The incidence rate of carotid plaque was higher in combined HC(65.9%)than in N-TC(44.5%)and isolated HC groups(56.0%)(P<0.01).IMT,number of plaque and incidence rate of carotid plaque were in no statistic difference among four subgroups of MS with normal cholesterol level(P>0.05).Stepwise regression analysis indicated that age and DBP were related to IMT while age was related to the number of plaque.Conclusions MS combining HC has much more significant influence on carotid artery atherosclerosis than high TG and low HDL-C.The age and DBP have significant influence on carotid artery atherosclerosis of MS with normal cholesterol.