Objective: To establish a scoring system for assessing the disease activity of thromboangiitis obliterans (TAO). Methods: One-hundred and four medical records from 88 TAO patients admitted during 2008 to 2013 were collected. The outcomes of the patients were classified as limb salvage and amputation, and the association between amputation and the clinical features and laboratory results that were potentially contributing to amputation were analyzed. The correlation coefficient of each factor with amputation was multiplied by 100 to obtain the risk score, and the cut-off value for amputation was obtained by receiver operating characteristic (ROC) curve analysis. Results: After univariate and multivariate analysis, 7 variables that included multiple digit ulcers, multiple digit gangrene, popliteal artery involvement, neutrophilic leukocytosis, anemia, hyperfibrinogenemia and thrombocytosis were finally chosen as assessing variables. The possible maximum score of the patient was 234, in which the clinical score was 86 and laboratory score was 148, respectively. The cut-off value of clinical score, laboratory score and total score was 53.5, 38.5 and 91, respectively. Conclusion: To a certain extent, this scoring system can be used for guiding the selection of effective treatment strategies for TAO patients. However, its accuracy still requires validation by further cohort studies.