Abstract: Objective To investigate the incidence and risk factors of new-onset atrial fibrillation (AF) after coronary artery bypass grafting (CABG). Methods A total of 247 patients with coronary heart disease who underwent CABG from January 2014 to November 2018 in the Affiliated Hospital of Xuzhou Medical University were enrolled and their clinical data were retrospectively analyzed. The patients were divided into an AF group and a NAF group, according to the onset of AF after surgery. The incidence of new-onset AF after CABG was calculated. Multivariate logistic regression analysis was performed to analyze the risk factors of new-onset AF after CABG. Results The incidence of postoperative new-onset AF was 23.9% (59/247). Multivariate logistic regression analysis showed that age (OR=1.097, 95%CI 1.038-1.159, P=0.001), erythrocyte distribution width (RDW) (OR=1.456, 95%CI 1.003-2.113, P=0.048), left atrial diameter (LAD) (OR=1.251, 95%CI 1.136-1.377, P<0.01), and the ratio of early diastolic transmitral velocity to early diastolic mitral annular velocity (E/E') before CABG (OR=1.172, 95% CI 1.019-1.348, P=0.026) were the independent risk factors for new-onset AF after CABG. Conclusions Age, RDW, LAD and E/E' before CABG may be independent risk factors for new-onset AF after CABG.