Background: The present study explored the relationship between metabolic syndrome (MetS) and chronic kidney disease (CKD) in patients with coronary artery disease (CAD) in China. Methods and Results: The prevalence of MetS and CKD were determined in 3,465 participants with CAD from the China Heart Survey, from June 1^st to August 31^st 2005. The relationship between MetS and CKD was analyzed. The prevalence of MetS and CKD was 53.0% and 21.1%, respectively. Patients with MetS had a higher prevalence of CKD than those without MetS. All traits of MetS except central obesity were statistically significantly associated with CKD. The multivariate-adjusted odds ratio (OR) of CKD in participants with and without MetS was 1.27 (95% confidence interval (CI) 1.07-1.51). In the multivariate-adjusted model, patients with 3 MetS components, excluding central obesity, had a higher OR for CKD (OR 2.17, 95%CI 1.21-3.88). Conclusions: MetS is a significantly higher risk factor for CKD in patients with CAD. Central obesity might attenuate the effect of MetS on CKD in patients with CKD, regardless of the number of MetS components. (Circ J 2010; 74: 462 - 467)