Introduction: We think it plausible that decreased antioxidative function, which might be present in paroxysmal atrial fibrillation (AF), and consequent increase of lipid peroxidation would provide the substrate predisposing to AF. Methods: This study enrolled 11 female patients with paroxysmal lone AF and a reference group of 10 age-matched females with structurally normal hearts and no history of AF. For evaluating the oxidation and antioxidant ability of lipoprotein, we tested the sensitivity of oxidation, antioxidant potential, level of glycation, the pattern of apolipoprotein expression, particle size, and phagocytosis by macrophage using copper-mediated LDL-oxidation, ferric reducing ability of plasma assay, paraoxonase assay, and electron microscopy, respectively. Results: The baseline characteristics showed no differences between 2 groups. The very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) in AF patients contained significantly higher content of malondialdehyde (p=0.019 and p=0.028, respectively). The cupric ion-mediated LDL oxidation was 1.6-fold more sensitive in AF group (T1/2max =27 vs. 44 minutes, p<0.05). In the high-density lipoprotein2 (HDL) and HDL3 fractions, the AF group had weaker antioxidant potentials demonstrating 30% weaker serum paraoxonase activity than the controls (p<0.05). Fluorescence measurement in all lipoprotein fractions revealed that VLDL and LDL from AF group had a greater extent of advanced glycated end products than controls (20% and 54%, respectively). Electron microscopy revealed that the AF group had a smaller particle size. Also, addition of VLDL (7.5g of protein) or LDL (16.5g of protein) in AF group into cell medium resulted in a much stronger red intensity than the same amount of those in controls, while PBS-treated cells did not exhibit red intensity. This result indicates that VLDL and LDL from the AF group could be more easily absorbed into macrophages by phagocytosis. Conclusions: This study showed the alteration of lipoprotein profiles in female patients with atrial fibrillation. All of these alterations are connected to lowered antioxidant ability of serum and elevated inflammatory parameters.