Abstract： AIM: To analyze the factors related to the recurrence of giant cell tumor (GCT) of long bone. METHODS: Clinical, radiological and laboratory data of 21 cases of recurrent GCT of long bone were analyzed. Methods of primary operation, locations of tumor, presence of pathological fracture and grade of tumor according to the Jaffe's and the Campanicci's classification were reviewed. RESULTS: All of the recurrent cases had had operation in other hospitals. According to the Jaffe's pathological grade, the grade of 17 cases with recurrent GCT did not change compared with the primary diagnosis. But according to the Campanicci's radiological grade, there were significant changes. 12 recurrent tumors were located at the proximal tibia and 11 had a local pathological fracture. In all the recurrent cases, intralesional excision (curettage) had been performed with some adjuvant treatment. CONCLUSION: The recurrence of GCT of long bone resulted from multiple related factors and the Campanicci's radiological grade is an important indicator of recurrence. If a pathological fracture exists at the site of the tumor, the recurrent rate increases remarkably. Intralesional excision (curettage) is, to some extent, responsible for the recurrence of GCT of long bone. Adjuvant procedures, such as treating the remnants of the tumor by zinc chloride, alcohol and H2O2 can not replace the thorough excision of the tumor.