Metabolic syndrome (MetS) confers increased risks of cardiovascular disease (CVD). Both vitamin D₃and adipocytokines (especially adiponectin and leptin) have a great impact on CVD and MetS. In vitamin D₃metabolism, the vitamin D₃25-hydroxylase (CYP27A1) and 25-hydroxyvitamin D₃1-alpha-hydroxylase (CYP27B1) are two key enzymes. This study aimed to examine the influence of vitamin D₃CYP27 single nucleotide polymorphisms (SNPs) on adipocytokines and MetS. Cross-sectional data and DNA samples were collected from male volunteers (n=649, age: 55.7 ± 4.7 years). Two tagging SNPs,CYP27A1 rs4674344andCYP27B1 rs10877012, were selected from the HapMap project. MetS was significantly associated with theCYP27A1 rs4674344SNP(P=0.04)and the ratio of adiponectin/leptin (A/L ratio) was most correlated to theCYP27A1 rs4674344SNP, appearing to be significantly lower in T-carriers than in AA subjects (3.7 ± 4.0 versus 5.1 ± 6.0,P=0.001) and significantly negatively associated after adjustment. For each MetS component associated with theCYP27A1 rs4674344SNP, the A/L ratios were significantly negative in preclinical stage (condition not meeting the individual criteria), except the blood pressure. In conclusion,CYP27A1 rs4674344SNP, A/L ratio, and MetS are significantly associated and T-carriers might have a higher risk of developing MetS due to low A/L ratios in the preclinical stage.