Abstract： Objectives To evaluate the association between serum cystatin C and carotid atherosclerosis.Methods Medical data,including physical examinations,serum levels of cystatin C,bilirubin,uric acid and other biochemical markers and duplex ultrasonographic scanning for the carotid artery,of 1741 healthy adults (1193 men and 548 women) who sought physical check-up at Peking Union Medical College Hospital during January 2010 and December 2011 were collected,and those with hypertension,diabetes and liver or renal function failure were excluded.Based on the results of carotid duplex uhrasonography,all the adults checked were assigned to two groups,one with thickened intima-media and atherosclerotic plaque (group A),the other with non-thickened intima-media and non-atherosclerotic plaque (group B).Difference in serum cystatin C,bilirubin,uric acid and other biochemical markers between the two groups was analyzed by using Student's t test.The correlation between the markers and carotid plaque was analyzed by using Spearman correlation analysis.The correlated factors of the carotid thickness and plaque appearance were analyzed by using unconditional Logistic regression analysis.Results Serum level of cystatin C was significantly increased in group A (t =-8.85,P ＜ 0.05).Thickness of carotid intima was positively correlated with serum cystatin C (r =0.21,P ＜ 0.05).In multivariate Logistic regression analysis,high level of serum cystatin C was not an independent risk factor of carotid atherosclerosis.Conclusion Relationship between serum cyatatin C and carotid atherosclerosis was not confirmed in our populations,which should be explored further in cohort studies.