Shi-Long Zhang,1,* Zhi-Ming Wang,2,3,* Wen-Rong Wang,4 Xin Wang,5 Yu-Hong Zhou21Institute of Fudan-Minhang Academic Health System, Minhang Branch, Zhongshan Hospital, Fudan University, Shanghai, 201199, People’s Republic of China; 2Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, 200032, People’s Republic of China; 3Department of Medical Oncology, Xiamen Branch, Zhongshan Hospital, Fudan University, Xiamen, 361000, People’s Republic of China; 4Faculty of Physical Education, Shandong Normal University, Jinan, 250014, People’s Republic of China; 5Department of Acupuncture and Moxibustion, Central Hospital of Shanghai, Xuhui District, Shanghai, 200031, People’s Republic of China*These authors contributed equally to this workBackground: The aim of the study was to build and validate practical nomograms to better predict the overall survival (OS) and cancer-specific survival (CSS) of the patients with soft tissue sarcomas (STS) who underwent surgery.Methods: Patient data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. We identified 8804 patients who underwent surgery with STS between 2007 and 2015, and randomly divided them into the training (n=6164) and validation (n=2640) cohorts. The Cox regression analysis and cumulative incidence function were performed to identify the independent prognostic factors associated with OS and CSS, respectively. The performance of the nomograms was evaluated using Harrell’s concordance index (C-index) and the calibration curves. Decision curve analysis (DCA) was introduced to compare the clinical practicality between the nomograms and the AJCC staging system.Results: Eight independent prognostic factors for OS and seven for CSS were determined and then used to build the nomograms for 3- and 5-year OS and CSS, respectively. The C-indexes of the nomograms for predicting OS were 0.788 in the internal validation and 0.823 in external validation, significantly higher than C-index of the AJCC staging system (P