To investigate the possible association between V249I and T280M polymorphisms and carotid atherosclerosis (CAS) in a Han population in northern China we studied 328 patients with increased carotid artery intima-media thickness (C-IMT) and 292 healthy controls with normal C-IMT. T280M and V249I polymorphic genotypes of CX3CR1 were determined by polymerase chain reaction restriction fragment length polymorphism. Results showed that the M280 allele frequency in CAS group was significantly lower than that in the controls. Logistic regression analysis revealed that the decreased frequency of the M280 allele was an independent risk factor for CAS.