Plasma D-dimer，a fibrin degradation product ，which is a sensitive and specific index of coagulation and fibrinolysis， can be used as an important indicator for the prediction of thrombosis. The study showed that the plasma D- dimer can predict thrombosis in patients with atrial fibrillation, and there is a certain value to guide the anticoagulant therapy. In this paper, the effect and clinical value of plasma D- dimer in the prediction of thrombosis in patients with atrial fibrillation were reviewed.