Objective To evaluate the influence of resection status, pathological type, pathological stage and postoperative adjuvant therapy on prognosis of surgically treated thymic carcinoma. Methods In this retrospective study, 56 patients with surgically treated thymic carcinoma in the Department of Thoracic Surgery, Peking Union Medical College Hospital from January 2005 to December 2015 were enrolled. There were 30 males and 26 females aged 52.1±11.5 years ranging from 22 to 81 years. The survival curve was performed by Kaplan-Meier method. The prognostic factors affecting overall survival (OS) and disease-free survival (DFS) were analyzed by one-way analysis of variance (ANOVA). Results R0 resection was performed in 37 patients (67.9%), and other resections in 19 (32.1%); 13 patients suffered thymic carcinoma with Masaoka stage Ⅰ-Ⅱ, 26 Ⅲ, and 17 Ⅳ. Low-grade thymic carcinoma was found in 42 patients, and high-grade in 14. Postoperative radiotherapy, chemotherapy and chemoradiotherapy were performed on 17, 12 and 18 patients respectively and 9 patients were untreated. Forty-one patients was followed up for 1 to 10 years, and the follow-up rate was 73%. The 1-, 3- and 5-year OS rates were 93%, 74% and 61%, respectively. Resection status and pathological stage affected OS. Postoperative radiotherapy after R0 resection affected DFS, but did not affect OS. Conclusion Most patients with thymic carcinoma after surgery can survive for a long period, and R0 resection is the most important prognostic factor of thymic carcinoma. Postoperative radiotherapy after R0 resection in patients with Masaoka stage Ⅱ-Ⅲ is recommended.