This is a report of 2 cases of central odontogenic fibroma of the mandible in 3 year-old female and 21 male patients. The results were as follows 1. The central odontogenic fibroma is a rare and benign odontogenic tumor and occurs usually in children and young adults. 2. Radiographically, its appearance it's a multilocular radiolucent lesion associated with unerupted or/and displaced teeth. 3. Histopathologically, it is composed of mature collagen fibers with numerous interspersed fibroblasts, and exhibits occasionally irregular calcified materials, 4. Conservative enucleation and curettage are the treatment of choice, and pathologic fracture tends to occur in child after operation.