Objective: To measure the concentration of growth differentiation factor-15 (GDF-15) in the serum of patients with atrial fibrillation (AF), to study the correlations between the levels of GDF-15 and different factors including basic clinical information, biochemical examinations, and atrial structure, and further to explore the association between GDF-15 and AF types and structural remodeling. Methods: AF patients who were admitted to the ward of the Department of Cardiology at Peking University Third Hospital between October 2017 and October 2019 were prospectively enrolled. Patients admitted to the ward at the same time with sinus rhythm and no prior AF history were enrolled in the control group. Clinical information and blood samples of the patients were collected. Enzyme-linked immunosorbent assay was used to measure the concentration of GDF-15. SPSS 23.0 was used for statistical analysis. Results: In the study, 156 AF patients (64 persistent AF and 92 paroxysmal AF) and 38 patients of the control group were included. Serum GDF-15 levels in the AF group were significantly higher than in the control group [1 112 (723, 1 525) ng/L vs. 697 (499, 825) ng/L, P < 0.001]. Serum GDF-15 levels in the persistent AF group were significantly higher than in the paroxysmal AF group [1 140 (858, 1 708) ng/L vs. 1 090 (662, 1 374) ng/L, P=0.047]. The area under the curve (AUC) of serum GDF-15 levels for prediction of AF was 0.736 (95%CI: 0.651-0.822, P < 0.001). The cut-off value was 843.2 ng/L with a sensitivity of 68.2% and a specificity of 78.9%. The AUC of serum GDF-15 levels for prediction of persistent AF was 0.594 (95%CI: 0.504-0.684, P=0.047). The cut-off va-lue was 771.5 ng/L with a sensitivity of 82.8% and a specificity of 35.9%. Spearman rank correlation analysis showed that the serum GDF-15 levels were positively correlated with age (r=0.480, P < 0.001), left atrial pressure (LAP, r=0.300, P < 0.001), and also negatively correlated with left atrial appendage flow velocity (LAAV, r=-0.252, P=0.002). Multiple linear regression analysis showed that age and LAP affected the GDF-15 levels significantly (P < 0.05). Logistic regression analysis suggested GDF-15 (OR=1.002, 95%CI: 1.001-1.003, P=0.004) and left atrial diameter (LAD, OR=1.400, 95%CI: 1.214-1.616, P < 0.001) were independent predictors of AF. Conclusions: Serum GDF-15 levels are higher in AF patients. Meanwhile, serum GDF-15 levels are higher in persistent AF patients than paroxysmal AF patients. GDF-15 is associated with AF and atrial structural remodeling.