We report on nine years experience of surgical treatment of mediastinal tumors in 47 patients. Their ages ranged from 5 o 67 years with an average of 36.4 years and the sex ratio of male and female was 1:1.5. The most frequent symptom was chest pain(27.7%), followed by ptosis(14.9%), general weatuless(12.8%) and eight patients(17.0%) were asymptomatic. The most prevalent location of the tumor was anterosuperior mediastinum(63.8%). Pathologically, thymoma(32.9%) was the most common tumor, followed by cyst(21.3%), neurogenic tumor(17.0%), germ cell tumor(12.8%), and mesenchymal tumor(6.4%). Complete removal was achieved in 41 cases of all benign tumors and 3 cases of malignant tumors. All the malignant tumor patients were treated with chemotherapy, radiotherapy or both after surgery. Postoperative complications developed in 4 cases and there was no operative death.