Objective: This study aimed to assess the role of coagulation-related indicators such as plasma fibrinogen (FIB), D-dimer, and fibrin degradation product (FDP) in rheumatoid arthritis (RA) and their association with disease activity.Methods: Data from 105 RA patients and 102 age- and gender- matched healthy controls were collected in the retrospective study. Disease activity score in 28 joints based on C-reactive protein (DAS28-CRP) was used to divide the RA patients into inactive group (DAS28-CRP ≤ 2.7) and active group (DAS28-CRP > 2.7). The association between plasma FIB, D-dimer, and FDP and DAS28-CRP was evaluated by spearman correlation. Receiver operating characteristic (ROC) curve was applied to determine the area under curve (AUC) value. The prognostic value of plasma FIB, D-dimer, and FDP in the RA disease activity was tested by logistical regression analysis.Results: RA patients showed higher FAR levels of plasma FIB, D-dimer, and FDP than the controls (P < 0.01). Plasma FIB, D-dimer, and FDP were also increased in active group of RA patients than those in inactive group (P < 0.001). Spearman analysis showed that plasma FIB, D-dimer, and FDP were positively related with DAS28-CRP (P < 0.001) in RA patients. ROC curve analyses revealed that the AUC of D-dimer was higher than ESR and RF, and that of FDP was higher than RF in RA patients. In addition, the optimal cut-off value of plasma FIB, D-dimer, and FDP for RA diagnosis was 286 mg/dL, 470 μg/L, and 1.45 mg/L, respectively. Logistical regression analyses showed that D-dimer (odds ratio = 2.862, 95% confidence interval: 1.851-4.426, P < 0.001) was a predictor for RA disease activity.Conclusions: FIB, D-dimer, and FDP were increased in RA patients and positively correlated with the disease activity of RA. D-dimer may act as a novel inflammatory parameter for predicting disease activity in RA patients.