Aim To explore the relationship between metabolic syndrome(MS)and arterial stiffness. Methods According to the international diabetes federation(IDF)consensus worldwide definition of the metabolic syndrome,522 patients and healthy subjects(273 men and 249 women,mean age 51.5±12.9 years)were enrolled and divided into 4 groups based on the amount of the component of MS,including control group,subgroup 1 with 1 component,subgroup 2 with 2 components and subgroup 3 with 3 or above components.Carotid-femoral pulse wave velocity(CFPWV)as an index reflecting large artery stiffness was measured by automatic PWV measuring system,and multiple regression analysis was performed in CFPWV and other correlative parameters. Results Compared with subjects in control group,subjects in MS subgroup 1,subgroup 2 and subgroup 3 had higher level of CFPWV(p<0.01 and 0.001 respectively),and the differences of CFPWV between subgroup 3 and subgroup 1,2 were significant(p<0.05).CFPWV was significantly correlated with age(r=0.432,p<0.001),systolic blood pressure(r=0.341,p<0.001),fasting plasma glucose(r=0.257,p<0.001), triglyceride(r=0.103,P=0.019) and waist(r=0.151,P=0.001),and stepwise multiple regression analysis demonstrated that age,systolic blood pressure and fasting plasma glucose were positively and independently related with CFPWV. Conclusions The clustering of components of MS may accelerate the occurrence and development of arterial stiffness.Measuring CFPWV as early as possible is helpful to primary prevention of cardiovascular events in the patients with components of metabolic syndrome.