The purpose of this study was to know the proper diagnosis and to establish the treatment plan of the osteosarcoma in the jaws through the clinical, radiological, and histopathologic considerations. The authors compared and analyzed the clinicoradiologic features of the six cases of osteosarcoma, diagnosed at the Dental college hospital in Yonsei University, Seoul, Korea, during the period from 1975 to 1995. The obtained results were as follows; 1. Osteosarcoma occurred in the mean age, 26.2 years, ranged from 14 to 35 years, and equally in men and women. 2. The swelling was the most common frequent presenting complaints. Other reported symtoms included pain, parasthesia of the lower lip or the lesion. 3. The average interval was seen 3.5 months before the patient had been seen by a doctor. 4. The frequency of the lesions was equally in the maxilla, 3 cases and mandible, 3 cases. 5. Radiologically, osteolytic lesions were 2 cases, mixed lesion 1 case, and sclerotic lesion were 3 cases. Periosteal reaction features were shown in 4 cases. A widening of the periodotnal lignament space, one of the earliest signs were shown in 2 cases. 6. Histopathologically, osteoblastic osteosarcoma which is seen in the 3 cases was the most frequent histologic type. Chondroblastic osteosarcoma were seen in the 2 cases. There was no correlation between the radiologic appearance and hitopathologic type.