The need for postoperative radiotherapy or chemotherapy for thymoma should be judged comprehensively according to clinical staging and surgical resection status. For early stage, i.e. Masaoka stage I and II, these lesions are limited and without distant metastasis generally do not need postoperative radiotherapy or chemotherapy; however, some stage II tumors that invade the surrounding organs and tissues or have distant metastasis should be treated with radiotherapy after surgery. Stage III and above thymoma, most of which will have metastasis or invasion of peripheral organs, can be treated with postoperative radiotherapy or chemotherapy even if it is completely resected in order to minimize recurrence; whereas for those who are not completely resected, adequate amount of postoperative radiotherapy is the standard treatment. Thymoma is more sensitive to radiation therapy, postoperative radiotherapy can effectively control the localization and improve the therapeutic effect, but not all people need postoperative radiotherapy. Therefore, it is recommended that the specific treatment means should be carried out under the guidance of specialized doctors and in conjunction with the patient’s own situation.