Kenaf is a plant having a high CO₂ absorption and growth rates. Therefore, we focused on kenaf as a CO₂ capture medium for small and medium stationary CO₂ emission sources such as garbage disposal plants. We propose CO₂ fixation at a high rate by cultivating kenaf under elevated CO₂ concentrations in exhaust gas, and utilization of the harvested kenaf as a fiber material. In this study, the cultivation experiment of kenaf was conducted under different CO₂ concentrations of 400 and 1500 ppm. As a result, kenaf grown under 1500 ppm showed higher growth and carbon fixation rates. Furthermore, fibers were extracted from the harvested kenaf stems. The results showed that the fiber yield under 1500 ppm cultivation was greater than that under 400 ppm cultivation even with the same stem length. However, no effect of CO₂ concentration on fiber dimensions was observed.