This study introduces high-temperature antioxidative carbon nanotubes (CNTs) derived from carbon dioxide (CO2). The individual CNT is coated by an amorphous boron layer that acts as a protection layer for carbon networks. It has a remarkable stability on thermal oxidation and provides a remarkable electrical conductivity of 4 S cm–1 at 1000 °C, while conventional carbon-based materials, including commercial CNTs, cannot maintain electrical properties because of oxidation below 400 °C. Thus, the novel atmospheric CO2-based chemical vapor decomposition route can contribute to the applications of carbon-based material in high-temperature oxidation conditions such as a solid oxide fuel cell.