To investigate the association of ATP binding cassette transporter A1 (ABCA1) gene R219K polymorphisms with atrial fibrillation (AF) in Chinese population.A total of 250 patients with AF and 250 control subjects were selected. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) was used to determine the ABCA1 genotype, and the serum concentration of C-reactive protein (CRP) and high-density lipoprotein cholesterol (HDL-C) were measured in all the subjects.The frequency of the RR , RK , KK , allele R , allele K genotype of ABCA1 in AF group and control group was 42.0%, 42.8%, 15.2%, 34.0%, 43.2% and 22.8%, 63.4%, 36.6%, 55.6%, 44.4%, respectively. The frequency of the KK genotype was significantly higher in the control group than in the case group (P=0.03), and the frequency of the allele K genotype was significantly different between the two groups (P=0.012). The serum CRP concentrations was significantly higher in AF group than in the control group (P=0.004), but serum HDL-C level showed no difference between the two groups. The serum CRP concentrations were significantly higher in patients with RR genotype than in those with KK genotype (P=0.013), and patients with RR genotype had significantly lower HDL-C level than those with RK and KK genotypes (P=0.009 and 0.027, respectively).Patients with AF have elevated serum CRP level in comparison with healthy individuals, and the K allele of R219K polymorphism is an independent protective factor against AF.