Introduction : Endothelial dysfunction, inflammation, abnormalities of coagulation system are associated with atrial fibrillation. Conversion to sinus rhythm may be accompanied by improvement of endothelial function. However, it is not certain how long time is required for restoration of these abnormalities. Methods and Results: Forty nine patients with persistent atrial fibrillation patients were enrolled. All patients had more than one episode of recurrence after conversion to sinus rhythm and duration of atrial fibrillation was 30짹21 months. Serum markers for endothelial function [von-Willebrand factor (vWF), thrombomodulin (TM)], inflammation [quantitative and high sensitive C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6(IL-6)], coagulation [fibrinogen, fibrinogen degradation product (FDP), d-dimer), platelet (p-selectin) were measured at baseline state and 2 months after restoration of sinus rhythm using antiarrhythmic agent (class I or III). Antithrombotic therapy was done in all patients according to ACC/AHA guideline. Left atrial diameter was reduced (47짹8 to 41짹8 mm, p=0.000) and left ventricular function increased (57짹13 to 63짹11%, p=0.015) after restoration of sinus rhythm. Even though markers for endothelial function [vWF (162짹46 to 154짹52%, p=0.326)], inflammation [q-CRP (0.93짹1.76 to 0.45짹0.42 p=0.082), hs-CRP (0.85짹1.94 to 0.41 to 0.75, p=0.136), IL-6 (19짹25 to 17짹21, p=0.754)], platelet [p-selectin (145짹127 to 141짹90, p=0.909)] showed tendency to improvement, those were not statically significant. Only markers for coagulation was reduced significantly [fibrinogen (320짹95 to 287짹80, p=0.034)] after restoration of sinus rhythm. Conclusion: Endothelial dysfunction, inflammation, platelet hyperactivity were not improved 2 months after restoration of sinus rhythm but coagulation abnormality improved most quickly after conversion to sinus rhythm.