The discovery of oncogenes and tumor suppressor genes have made it possible to partly understand the mechanism of cancer development. It is generally accepted that the cancer development is caused by specific gene alterations and now more than 100 oncogenes and suppressor genes are known to be involved in human carcinogenesis. However, there are only a few reports about oncogene expression on bone tumors. The author carried out an immunohistochemical study to reveal the oncogene and suppressor genes on carcinogenesis of bone tumors using antibodies against c-myc, c-H-ras, p53 and EGF. In 32 cases of osteochondrorma, EGF, p53 and c-myc antisera revealed positive reaction in 4 (12.5%), 2 (6.3%) and 7 (21.9%) cases, and, in 4 cases of chondrosarcoma, c-myc antisera revealed positive reaction in 2 (50%) cases. In 21 cases of osteosarcoma, the positive reaction of p53 was noted in 10 (47.6%) cases and that of c-myc in 3 (14.3%) cases. In 14 cases of fibrous bone tumors, there are only 2 (14.3%) cases of positive reaction with p53. These results suggest some roles of the p53 and c-myc genes in osteosarcoma development and c-myc gene in osteochondroma and chondrosarcoma development.