Malignant fibrous histiocytoma was classified as fibrosarcoma, liposarcoma, rhabdomyosarcoma in times past and it was first introduced in 1963 to refer to a group of soft tissue tumors and reported in bone in 1972. It was postulated that the origin of tumor cell was derived from histiocytes that could assume the appearance and function of fibroblasts("facultative fibroblasts") at first. But, recently the immunohistochemical studies suggested origin from a primitive mesenchymal cell. The malignant fibrous histiocytoma were commonly misdiagnosed as other tumors such as myxoid liposarcoma, pleomorphic rhabdomyosarcoma, osteogenic sarcoma, leiomyosarcoma, malignant schwannoma, giant cell tumor, hemangiopericytoma, dermatofibrosarcoma protuberans due to the broad morphologic spectrum. The seventeen cases of the malignant fibrous histiocytomas diagnosed at Hanyang University Hospital since 1979 were reviwed, and the suggestions are as follows : 1. No fundamental histologic differences between the MFHs of soft tissues and bones. 2. The other tumors must be excluded in order to diagnose MFH due to wide histologic variety of MFH. 3. The review of the initial tissue slide was necessary for adequate diagnosis because the recurrent MFHs showed different histologic findings from original tumors.