There is a hard bag behind the ear without pain or itching, and the common causes are mainly as follows: a. Localized lipoma, due to the fat tissue behind the ear, abnormal accumulation of the formation of lumps. At this time, the smaller size of the lipoma, will not cause obvious pain symptoms, less impact on the patient, belongs to the benign lesions, the patient can be closely observed, do not need surgical resection. If in the process of close observation, the size of lipoma becomes bigger and accompanied by swelling and pain, surgical resection can be considered. Secondly, the hard bag formed by malignant tumor metastasis is mostly seen in nasopharyngeal carcinoma patients, in which the tumor cells invade the tissues behind the ear along the lymphatic tube and form a hard bag. At this time, patients need to improve the local CT examination to clarify the location of primary tumor, and perform resection of primary tumor plus lymph node dissection as early as possible. After surgery, combine with local radiotherapy to inhibit the growth of tumor cells and avoid the recurrence of postauricular mass.